org.apache.sis.metadata/org/apache/sis/metadata/iso/citation/Citations.html - sis-site - Git at Google

 <!DOCTYPE HTML>
 <html lang="en">
 <head>
 <!-- Generated by javadoc (21) on Thu Oct 05 19:54:57 CEST 2023 -->
 <title>Citations (Apache SIS 1.4 API)</title>
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <meta name="dc.created" content="2023-10-05">
 <meta name="description" content="declaration: module: org.apache.sis.metadata, package: org.apache.sis.metadata.iso.citation, class: Citations">
 <meta name="generator" content="javadoc/ClassWriterImpl">
 <meta name="keywords" content="org.apache.sis.metadata.iso.citation.Citations class">
 <meta name="keywords" content="ISO_19115">
 <meta name="keywords" content="EPSG">
 <meta name="keywords" content="WMS">
 <meta name="keywords" content="OGC">
 <meta name="keywords" content="ESRI">
 <meta name="keywords" content="WMO">
 <meta name="keywords" content="NETCDF">
 <meta name="keywords" content="GEOTIFF">
 <meta name="keywords" content="PROJ4">
 <meta name="keywords" content="MAP_INFO">
 <meta name="keywords" content="S57">
 <meta name="keywords" content="ISBN">
 <meta name="keywords" content="ISSN">
 <meta name="keywords" content="SIS">
 <meta name="keywords" content="values()">
 <meta name="keywords" content="fromName()">
 <meta name="keywords" content="titleMatches()">
 <meta name="keywords" content="identifierMatches()">
 <meta name="keywords" content="getIdentifier()">
 <meta name="keywords" content="toCodeSpace()">
 <link rel="stylesheet" type="text/css" href="../../../../../../../stylesheet.css" title="Style">
 <link rel="stylesheet" type="text/css" href="../../../../../../../sis.css" title="Style">
 <link rel="stylesheet" type="text/css" href="../../../../../../../script-dir/jquery-ui.min.css" title="Style">
 <script type="text/javascript" src="../../../../../../../script.js"></script>
 <script type="text/javascript" src="../../../../../../../script-dir/jquery-3.6.1.min.js"></script>
 <script type="text/javascript" src="../../../../../../../script-dir/jquery-ui.min.js"></script>
 </head>
 <body class="class-declaration-page">
 <script type="text/javascript">var pathtoroot = "../../../../../../../";
 loadScripts(document, 'script');</script>
 <noscript>
 <div>JavaScript is disabled on your browser.</div>
 </noscript>
 <div class="flex-box">
 <header role="banner" class="flex-header">
 <nav role="navigation">
 <!-- ========= START OF TOP NAVBAR ======= -->
 <div class="top-nav" id="navbar-top"><button id="navbar-toggle-button" aria-controls="navbar-top" aria-expanded="false" aria-label="Toggle navigation links"><span class="nav-bar-toggle-icon">&nbsp;</span><span class="nav-bar-toggle-icon">&nbsp;</span><span class="nav-bar-toggle-icon">&nbsp;</span></button>
 <div class="skip-nav"><a href="#skip-navbar-top" title="Skip navigation links">Skip navigation links</a></div>
 <ul id="navbar-top-firstrow" class="nav-list" title="Navigation">
 <li><a href="../../../../../../../index.html">Overview</a></li>
 <li><a href="../../../../../../module-summary.html">Module</a></li>
 <li><a href="package-summary.html">Package</a></li>
 <li class="nav-bar-cell1-rev">Class</li>
 <li><a href="package-tree.html">Tree</a></li>
 <li><a href="../../../../../../../deprecated-list.html">Deprecated</a></li>
 <li><a href="../../../../../../../index-all.html">Index</a></li>
 <li><a href="../../../../../../../help-doc.html#class">Help</a></li>
 </ul>
 <ul class="sub-nav-list-small">
 <li>
 <p>Summary:</p>
 <ul>
 <li>Nested</li>
 <li><a href="#field-summary">Field</a></li>
 <li>Constr</li>
 <li><a href="#method-summary">Method</a></li>
 </ul>
 </li>
 <li>
 <p>Detail:</p>
 <ul>
 <li><a href="#field-detail">Field</a></li>
 <li>Constr</li>
 <li><a href="#method-detail">Method</a></li>
 </ul>
 </li>
 </ul>
 </div>
 <div class="sub-nav">
 <div id="navbar-sub-list">
 <ul class="sub-nav-list">
 <li>Summary:&nbsp;</li>
 <li>Nested&nbsp;|&nbsp;</li>
 <li><a href="#field-summary">Field</a>&nbsp;|&nbsp;</li>
 <li>Constr&nbsp;|&nbsp;</li>
 <li><a href="#method-summary">Method</a></li>
 </ul>
 <ul class="sub-nav-list">
 <li>Detail:&nbsp;</li>
 <li><a href="#field-detail">Field</a>&nbsp;|&nbsp;</li>
 <li>Constr&nbsp;|&nbsp;</li>
 <li><a href="#method-detail">Method</a></li>
 </ul>
 </div>
 <div class="nav-list-search"><a href="../../../../../../../search.html">SEARCH</a>
 <input type="text" id="search-input" disabled placeholder="Search">
 <input type="reset" id="reset-button" disabled value="reset">
 </div>
 </div>
 <!-- ========= END OF TOP NAVBAR ========= -->
 <span class="skip-nav" id="skip-navbar-top"></span></nav>
 </header>
 <div class="flex-content">
 <main role="main">
 <!-- ======== START OF CLASS DATA ======== -->
 <div class="header">
 <div class="sub-title"><span class="module-label-in-type">Module</span>&nbsp;<a href="../../../../../../module-summary.html">org.apache.sis.metadata</a></div>
 <div class="sub-title"><span class="package-label-in-type">Package</span>&nbsp;<a href="package-summary.html">org.apache.sis.metadata.iso.citation</a></div>
 <h1 title="Class Citations" class="title">Class Citations</h1>
 </div>
 <div class="inheritance" title="Inheritance Tree"><a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html" title="class or interface in java.lang" class="external-link">Object</a>
 <div class="inheritance"><a href="../../../../../../../org.apache.sis.util/org/apache/sis/util/Static.html" title="class in org.apache.sis.util">Static</a>
 <div class="inheritance">Citations</div>
 </div>
 </div>
 <section class="class-description" id="class-description">
 <hr>
 <div class="type-signature"><span class="modifiers">public final class </span><span class="element-name type-name-label">Citations</span>
 <span class="extends-implements">extends <a href="../../../../../../../org.apache.sis.util/org/apache/sis/util/Static.html" title="class in org.apache.sis.util">Static</a></span></div>
 <div class="block">A set of predefined constants and static methods working on <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">citations</a>.
  This class provides two kinds of <code>Citation</code> constants:

  <ul>
    <li>Instances of <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link"><code>Citation</code></a> are references mostly for human reading.</li>
    <li>Instances of <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml"><code>IdentifierSpace</code></a> provide the code spaces for identifiers
        (most often <a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/crs/AbstractCRS.html" title="class in org.apache.sis.referencing.crs">Coordinate Reference System</a> identifiers)
        together with information about who maintains those identifiers.</li>
  </ul>

  For example <code>"EPSG:4326"</code> is a widely-used identifier
  for the <cite>“World Geodetic System (WGS) 1984”</cite> Coordinate Reference System (CRS).
  The <code>"4326"</code> part is the identifier <a href="../DefaultIdentifier.html#getCode()">code</a> and
  the <code>"EPSG"</code> part is the identifier <a href="../DefaultIdentifier.html#getCodeSpace()">code space</a>.
  The meaning of codes in that code space is controlled by an <a href="../DefaultIdentifier.html#getAuthority()">authority</a>,
  the <cite>“EPSG Geodetic Parameter Dataset”</cite>. The <a href="DefaultCitation.html#getCitedResponsibleParties()">cited
  responsible party</a> for the EPSG dataset is the <cite>“International Association of Oil &amp; Gas producers”</cite> (IOGP).

  <p>The constants defined in this class are typically values returned by:</p>
  <ul>
    <li><a href="DefaultCitation.html#getIdentifiers()"><code>DefaultCitation.getIdentifiers()</code></a> for the <a href="#ISBN"><code>ISBN</code></a> and <a href="#ISSN"><code>ISSN</code></a> constants.</li>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a> for other <code>IdentifierSpace</code> constants.</li>
    <li><a href="../DefaultMetadata.html#getMetadataStandards()"><code>DefaultMetadata.getMetadataStandards()</code></a> for other <code>Citation</code> constants.</li>
  </ul>

  The static methods defined in this class are for:
  <ul>
    <li>Inferring an identifier from a citation (this is useful mostly with <code>IdentifierSpace</code> instances).</li>
    <li>Determining if two instances can be considered the same <code>Citation</code> by comparing their titles or
        their identifiers.</li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.3</dd>
 </dl>
 </section>
 <section class="summary">
 <ul class="summary-list">
 <!-- =========== FIELD SUMMARY =========== -->
 <li>
 <section class="field-summary" id="field-summary">
 <h2>Field Summary</h2>
 <div class="caption"><span>Fields</span></div>
 <div class="summary-table three-column-summary">
 <div class="table-header col-first">Modifier and Type</div>
 <div class="table-header col-second">Field</div>
 <div class="table-header col-last">Description</div>
 <div class="col-first even-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#EPSG" class="member-name-link">EPSG</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The authority for identifiers of objects defined by the
  <a href="https://epsg.org/">EPSG Geodetic Parameter Dataset</a>.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second odd-row-color"><code><a href="#ESRI" class="member-name-link">ESRI</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The authority for identifiers of objects defined by <a href="https://www.esri.com">ESRI</a>.</div>
 </div>
 <div class="col-first even-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#GEOTIFF" class="member-name-link">GEOTIFF</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The authority for identifiers of objects defined by the
  the <a href="https://www.ogc.org/standards/geotiff">GeoTIFF</a> specification.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second odd-row-color"><code><a href="#ISBN" class="member-name-link">ISBN</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The <cite>International Standard Book Number</cite> (ISBN) defined by ISO-2108.</div>
 </div>
 <div class="col-first even-row-color"><code>static final <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html" title="class or interface in java.util" class="external-link">List</a><wbr>&lt;<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#ISO_19115" class="member-name-link">ISO_19115</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The <cite>Geographic Information — Metadata</cite> standards defined by ISO 19115.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second odd-row-color"><code><a href="#ISSN" class="member-name-link">ISSN</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The <cite>International Standard Serial Number</cite> (ISSN) defined by ISO-3297.</div>
 </div>
 <div class="col-first even-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#MAP_INFO" class="member-name-link">MAP_INFO</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The authority for identifiers of objects defined by MapInfo.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second odd-row-color"><code><a href="#NETCDF" class="member-name-link">NETCDF</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The authority for identifiers of objects defined by the netCDF specification.</div>
 </div>
 <div class="col-first even-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#OGC" class="member-name-link">OGC</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The authority for identifiers found in specifications from the
  <a href="https://www.ogc.org/">Open Geospatial Consortium</a>.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second odd-row-color"><code><a href="#PROJ4" class="member-name-link">PROJ4</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The authority for identifiers of objects defined by the <a href="https://proj.org/">PROJ</a> project.</div>
 </div>
 <div class="col-first even-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#S57" class="member-name-link">S57</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The <cite>IHO transfer standard for digital hydrographic data</cite> specification.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a></code></div>
 <div class="col-second odd-row-color"><code><a href="#SIS" class="member-name-link">SIS</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The codespace of objects that are specific to the <a href="https://sis.apache.org/">Apache SIS</a> project.</div>
 </div>
 <div class="col-first even-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</code></div>
 <div class="col-second even-row-color"><code><a href="#WMO" class="member-name-link">WMO</a></code></div>
 <div class="col-last even-row-color">
 <div class="block">The authority for identifiers of objects defined by the
  <a href="https://www.wmo.int">World Meteorological Organization</a>.</div>
 </div>
 <div class="col-first odd-row-color"><code>static final <a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a><wbr>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</code></div>
 <div class="col-second odd-row-color"><code><a href="#WMS" class="member-name-link">WMS</a></code></div>
 <div class="col-last odd-row-color">
 <div class="block">The authority for identifiers of objects defined by the
  <a href="https://www.ogc.org/standards/wms">Web Map Service</a> (WMS) specification.</div>
 </div>
 </div>
 </section>
 </li>
 <!-- ========== METHOD SUMMARY =========== -->
 <li>
 <section class="method-summary" id="method-summary">
 <h2>Method Summary</h2>
 <div id="method-summary-table">
 <div class="table-tabs" role="tablist" aria-orientation="horizontal"><button id="method-summary-table-tab0" role="tab" aria-selected="true" aria-controls="method-summary-table.tabpanel" tabindex="0" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table', 3)" class="active-table-tab">All Methods</button><button id="method-summary-table-tab1" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab1', 3)" class="table-tab">Static Methods</button><button id="method-summary-table-tab4" role="tab" aria-selected="false" aria-controls="method-summary-table.tabpanel" tabindex="-1" onkeydown="switchTab(event)" onclick="show('method-summary-table', 'method-summary-table-tab4', 3)" class="table-tab">Concrete Methods</button></div>
 <div id="method-summary-table.tabpanel" role="tabpanel">
 <div class="summary-table three-column-summary" aria-labelledby="method-summary-table-tab0">
 <div class="table-header col-first">Modifier and Type</div>
 <div class="table-header col-second">Method</div>
 <div class="table-header col-last">Description</div>
 <div class="col-first even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a></code></div>
 <div class="col-second even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#fromName(java.lang.String)" class="member-name-link">fromName</a><wbr>(<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;identifier)</code></div>
 <div class="col-last even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Returns a citation of the given identifier.</div>
 </div>
 <div class="col-first odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></code></div>
 <div class="col-second odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#getIdentifier(org.opengis.metadata.citation.Citation)" class="member-name-link">getIdentifier</a><wbr>(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation)</code></div>
 <div class="col-last odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Infers an identifier from the given citation, or returns <code>null</code> if no identifier has been found.</div>
 </div>
 <div class="col-first even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static boolean</code></div>
 <div class="col-second even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#identifierMatches(org.opengis.metadata.citation.Citation,java.lang.String)" class="member-name-link">identifierMatches</a><wbr>(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation,
  <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;identifier)</code></div>
 <div class="col-last even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Returns <code>true</code> if at least one <a href="DefaultCitation.html#getIdentifiers()">identifier</a>
  in the given citation have a <a href="../DefaultIdentifier.html#getCode()">code</a> matching the given
  string.</div>
 </div>
 <div class="col-first odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static boolean</code></div>
 <div class="col-second odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#identifierMatches(org.opengis.metadata.citation.Citation,org.opengis.metadata.citation.Citation)" class="member-name-link">identifierMatches</a><wbr>(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c1,
  <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c2)</code></div>
 <div class="col-last odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Returns <code>true</code> if at least one <a href="DefaultCitation.html#getIdentifiers()">identifier</a>
  <a href="../DefaultIdentifier.html#getCode()">code</a> in <code>c1</code> is equal to an identifier code in
  <code>c2</code>.</div>
 </div>
 <div class="col-first even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static boolean</code></div>
 <div class="col-second even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#titleMatches(org.opengis.metadata.citation.Citation,java.lang.String)" class="member-name-link">titleMatches</a><wbr>(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation,
  <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;title)</code></div>
 <div class="col-last even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Returns <code>true</code> if the <a href="DefaultCitation.html#getTitle()">title</a> or any
  <a href="DefaultCitation.html#getAlternateTitles()">alternate title</a> in the given citation
  matches the given string.</div>
 </div>
 <div class="col-first odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static boolean</code></div>
 <div class="col-second odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#titleMatches(org.opengis.metadata.citation.Citation,org.opengis.metadata.citation.Citation)" class="member-name-link">titleMatches</a><wbr>(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c1,
  <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c2)</code></div>
 <div class="col-last odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Returns <code>true</code> if at least one <a href="DefaultCitation.html#getTitle()">title</a> or
  <a href="DefaultCitation.html#getAlternateTitles()">alternate title</a> in <code>c1</code> is leniently
  equal to a title or alternate title in <code>c2</code>.</div>
 </div>
 <div class="col-first even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></code></div>
 <div class="col-second even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#toCodeSpace(org.opengis.metadata.citation.Citation)" class="member-name-link">toCodeSpace</a><wbr>(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation)</code></div>
 <div class="col-last even-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Infers a code space from the given citation, or returns <code>null</code> if none.</div>
 </div>
 <div class="col-first odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code>static <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>[]</code></div>
 <div class="col-second odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4"><code><a href="#values()" class="member-name-link">values</a>()</code></div>
 <div class="col-last odd-row-color method-summary-table method-summary-table-tab1 method-summary-table-tab4">
 <div class="block">Returns the values declared in this <code>Citations</code> class.</div>
 </div>
 </div>
 </div>
 </div>
 <div class="inherited-list">
 <h3 id="methods-inherited-from-class-Object">Methods inherited from class&nbsp;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html" title="class or interface in java.lang" class="external-link">Object</a></h3>
 <code><a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#clone()" title="class or interface in java.lang" class="external-link">clone</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#equals(java.lang.Object)" title="class or interface in java.lang" class="external-link">equals</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#finalize()" title="class or interface in java.lang" class="external-link">finalize</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#getClass()" title="class or interface in java.lang" class="external-link">getClass</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#hashCode()" title="class or interface in java.lang" class="external-link">hashCode</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#notify()" title="class or interface in java.lang" class="external-link">notify</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#notifyAll()" title="class or interface in java.lang" class="external-link">notifyAll</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#toString()" title="class or interface in java.lang" class="external-link">toString</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#wait()" title="class or interface in java.lang" class="external-link">wait</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#wait(long)" title="class or interface in java.lang" class="external-link">wait</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Object.html#wait(long,int)" title="class or interface in java.lang" class="external-link">wait</a></code></div>
 </section>
 </li>
 </ul>
 </section>
 <section class="details">
 <ul class="details-list">
 <!-- ============ FIELD DETAIL =========== -->
 <li>
 <section class="field-details" id="field-detail">
 <h2>Field Details</h2>
 <ul class="member-list">
 <li>
 <section class="detail" id="ISO_19115">
 <h3>ISO_19115</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html" title="class or interface in java.util" class="external-link">List</a>&lt;<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&gt;</span>&nbsp;<span class="element-name">ISO_19115</span></div>
 <div class="block">The <cite>Geographic Information — Metadata</cite> standards defined by ISO 19115.
  This list contains two standards published by the
  <a href="https://www.iso.org/">International Organization for Standardization</a>:

  <ul>
    <li>ISO 19115-1 Geographic Information — Metadata Part 1: Fundamentals</li>
    <li>ISO 19115-2 Geographic Information — Metadata Part 2: Extensions for imagery and gridded data</li>
  </ul>

  Apache SIS always uses those standards together (actually the SIS's API is a merge of those two standards,
  providing for example a unified view of <code>MI_Band</code> and <code>MD_Band</code>). This is why those standards
  are defined in a collection rather than as separated constants.

  <h4 id="content-and-future-evolution-heading">Content and future evolution</h4>
  The content of this list may vary in future Apache SIS versions depending on the evolution of standards
  and in the way that SIS support them. The current content is:

  <ul>
    <li><a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/annotation/Specification.html#ISO_19115" title="class or interface in org.opengis.annotation" class="external-link">ISO 19115-1:2014</a> at index 0.</li>
    <li><a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/annotation/Specification.html#ISO_19115_2" title="class or interface in org.opengis.annotation" class="external-link">ISO 19115-2:2019</a> at index 1.</li>
  </ul>

  <h4 id="main-usage-heading">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../DefaultMetadata.html#getMetadataStandards()"><code>DefaultMetadata.getMetadataStandards()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.6</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="EPSG">
 <h3>EPSG</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</span>&nbsp;<span class="element-name">EPSG</span></div>
 <div class="block">The authority for identifiers of objects defined by the
  <a href="https://epsg.org/">EPSG Geodetic Parameter Dataset</a>.
  EPSG is not an organization by itself, but is the <em>identifier space</em> managed by the
  <a href="https://www.iogp.org/">International Association of Oil &amp; Gas producers</a> (IOGP) organization
  for <a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/crs/AbstractCRS.html" title="class in org.apache.sis.referencing.crs">Coordinate Reference System</a> identifiers.
  EPSG is the default namespace of map projection method and parameter names in Apache SIS.

  <div class="note"><b>Historical note:</b>
  The EPSG acronym meaning was <cite>“European Petroleum Survey Group”</cite>.
  But this meaning does not apply anymore since the European and American associations merged into
  the <cite>“Association of Oil &amp; Gas producers”</cite> (OGP), later renamed as IOGP.
  The legacy acronym now applies only to the database Coordinate Reference System definitions,
  known as <cite>“EPSG Geodetic Parameter Dataset”</cite>.</div>

  The citation <a href="DefaultCitation.html#getCitedResponsibleParties()">responsible party</a> is
  the IOGP organization, but the <a href="../../../xml/IdentifierSpace.html#getName()">namespace</a> is <code>"EPSG"</code>.

  <h4 id="when-to-use-epsg-and-iogp--heading">When to use "EPSG" and "IOGP"</h4>
  For all usages except GML, the <code>"EPSG"</code> namespace shall be used for identifying
  <a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/crs/AbstractCRS.html" title="class in org.apache.sis.referencing.crs">Coordinate Reference System</a> objects.
  But in the particular case of GML, both <code>"EPSG"</code> and <code>"IOGP"</code> appear in different locations.
  For example:


 <div class="snippet-container"><button class="copy snippet-copy" aria-label="Copy snippet" onclick="copySnippet(this)"><span data-copied="Copied!">Copy</span><img src="../../../../../../../copy.svg" alt="Copy snippet"></button>
 <pre class="snippet"><code class="language-xml">  &lt;gml:identifier codeSpace="IOGP"&gt;urn:ogc:def:crs:EPSG::4326&lt;/gml:identifier&gt;
 </code></pre>
 </div>


  Guidelines:
  <ul>
    <li>The <code>"EPSG"</code> name shall be used in URN. This part of the URN is called "the authority" and
        is returned by both <code>Identifier.getAuthority()</code> and <code>Identifier.getCodeSpace()</code>.</li>
    <li>The <code>"IOGP"</code> name appears in the GML <code>codeSpace</code> attribute, but despite the attribute name this
        is <strong>not</strong> the <code>Identifier.getCodeSpace()</code> value of the <code>"EPSG:4326"</code> identifier.
        Instead, Apache SIS considers <code>"IOGP"</code> as the codespace of the <code>"IOGP:EPSG"</code> identifier,
        which is the <a href="DefaultCitation.html#getIdentifiers()">identifier of this citation</a>.</li>
  </ul>

  In other words, Apache SIS considers "IOGP" as the codespace of the "EPSG" codespace, but there is usually
  no need to go to such depth in identifier hierarchy except when handling GML documents. For this reason,
  the <code>"IOGP:EPSG"</code> identifier is handled in a special way by <a href="#getIdentifier(org.opengis.metadata.citation.Citation)"><code>getIdentifier(Citation)</code></a>,
  which return only <code>"EPSG"</code>.

  <h4 id="main-usage-heading1">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/factory/ConcurrentAuthorityFactory.html#getAuthority()"><code>ConcurrentAuthorityFactory.getAuthority()</code></a>
        with the addition of version information.</li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.4</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="WMS">
 <h3>WMS</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</span>&nbsp;<span class="element-name">WMS</span></div>
 <div class="block">The authority for identifiers of objects defined by the
  <a href="https://www.ogc.org/standards/wms">Web Map Service</a> (WMS) specification.
  The WMS 1.3 specifications is also known as ISO 19128
  <cite>Geographic Information — Web map server interface</cite> standard.

  <p>The citation <a href="DefaultCitation.html#getCitedResponsibleParties()">responsible parties</a>
  are the OGC and ISO organizations.
  The <a href="../../../xml/IdentifierSpace.html#getName()">namespace</a> declared by this constant is <code>"OGC"</code>,
  but the <code>"CRS"</code>, <code>"AUTO"</code> and <code>"AUTO2"</code> namespaces are also commonly found in practice.</p>

  <h4 id="main-usage-heading2">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/factory/CommonAuthorityFactory.html#getAuthority()"><code>CommonAuthorityFactory.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.7</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="OGC">
 <h3>OGC</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">OGC</span></div>
 <div class="block">The authority for identifiers found in specifications from the
  <a href="https://www.ogc.org/">Open Geospatial Consortium</a>.
  The <a href="../../../xml/IdentifierSpace.html#getName()">name</a> of this identifier space is fixed to <code>"OGC"</code>.
  Apache SIS uses this authority mostly for map projection methods and parameters as they were defined in older
  OGC specifications (in more recent specifications, <a href="#EPSG">EPSG</a> identifiers tend to be more widely used).

  <h4 id="example-heading">Example</h4>
  The Mercator projection can be defined by an operation method having the <code>"OGC:Mercator_1SP"</code> identifier
  and the following parameters:

  <table class="sis">
  <caption>Example of identifiers in OGC name space</caption>
  <tr><th>Name in OGC namespace</th>           <th>Name in default namespace (EPSG)</th></tr>
  <tr><td><code>"OGC:semi_major"</code></td>        <td></td></tr>
  <tr><td><code>"OGC:semi_minor"</code></td>        <td></td></tr>
  <tr><td><code>"OGC:latitude_of_origin"</code></td><td>Latitude of natural origin</td></tr>
  <tr><td><code>"OGC:central_meridian"</code></td>  <td>Longitude of natural origin</td></tr>
  <tr><td><code>"OGC:scale_factor"</code></td>      <td>Scale factor at natural origin</td></tr>
  <tr><td><code>"OGC:false_easting"</code></td>     <td>False easting</td></tr>
  <tr><td><code>"OGC:false_northing"</code></td>    <td>False northing</td></tr>
  </table>

  <h4 id="specifications-referenced-heading">Specifications referenced</h4>
  The specification actually referenced by this citation is implementation dependent
  and may change in future SIS version. Some of the specifications used are:

  <ul>
    <li><a href="https://www.ogc.org/">Coordinate Transformation Service</a></li>
    <li><a href="https://www.ogc.org/standards/wms">Web Map Service</a></li>
    <li><a href="https://portal.ogc.org/files/?artifact_id=24045">Definition identifier URNs in OGC namespace</a></li>
  </ul>

  We do not commit to a particular OGC specification in order to keep the flexibility to change the
  <a href="DefaultCitation.html#getTitle()">title</a> or URL according newer OGC publications.

  <h4 id="main-usage-heading3">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>See Also:</dt>
 <dd>
 <ul class="tag-list">
 <li><a href="#EPSG"><code>EPSG</code></a></li>
 <li><a href="#ESRI"><code>ESRI</code></a></li>
 </ul>
 </dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="ESRI">
 <h3>ESRI</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">ESRI</span></div>
 <div class="block">The authority for identifiers of objects defined by <a href="https://www.esri.com">ESRI</a>.
  The <a href="../../../xml/IdentifierSpace.html#getName()">name</a> of this identifier space is fixed to <code>"ESRI"</code>.
  This citation is used as the authority for many map projection method and parameter names
  other than the <a href="#EPSG">EPSG</a> ones.

  <h4 id="compatibility-note-heading">Compatibility note</h4>
  Many parameter names defined by <a href="#OGC">OGC</a> are very similar to the ESRI ones,
  except for the case. Examples:

  <table class="sis">
  <caption>Example of identifiers in ESRI name space</caption>
  <tr><th>Name in ESRI namespace</th>           <th>Name in OGC namespace</th></tr>
  <tr><td><code>"ESRI:Semi_Major"</code></td>        <td><code>"OGC:semi_major"</code></td></tr>
  <tr><td><code>"ESRI:Semi_Minor"</code></td>        <td><code>"OGC:semi_minor"</code></td></tr>
  <tr><td><code>"ESRI:Latitude_Of_Origin"</code></td><td><code>"OGC:latitude_of_origin"</code></td></tr>
  <tr><td><code>"ESRI:Central_Meridian"</code></td>  <td><code>"OGC:central_meridian"</code></td></tr>
  <tr><td><code>"ESRI:Scale_Factor"</code></td>      <td><code>"OGC:scale_factor"</code></td></tr>
  <tr><td><code>"ESRI:False_Easting"</code></td>     <td><code>"OGC:false_easting"</code></td></tr>
  <tr><td><code>"ESRI:False_Northing"</code></td>    <td><code>"OGC:false_northing"</code></td></tr>
  </table>

  <h4 id="main-usage-heading4">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.4</dd>
 <dt>See Also:</dt>
 <dd>
 <ul class="tag-list">
 <li><a href="#OGC"><code>OGC</code></a></li>
 <li><a href="#EPSG"><code>EPSG</code></a></li>
 </ul>
 </dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="WMO">
 <h3>WMO</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">WMO</span></div>
 <div class="block">The authority for identifiers of objects defined by the
  <a href="https://www.wmo.int">World Meteorological Organization</a>.
  The <a href="../../../xml/IdentifierSpace.html#getName()">name</a> of this identifier space is fixed to <code>"WMO"</code>.
  This citation is used as the authority for some coordinate operations other than EPSG and ESRI ones,
  for example "Rotated latitude/longitude".</div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>1.2</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="NETCDF">
 <h3>NETCDF</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">NETCDF</span></div>
 <div class="block">The authority for identifiers of objects defined by the netCDF specification.
  The <a href="../../../xml/IdentifierSpace.html#getName()">name</a> of this identifier space is fixed to <code>"NetCDF"</code>.
  This citation is used as the authority for some map projection method and parameter names
  as used in netCDF files.

  <h4 id="example-heading1">Example</h4>
  The Mercator projection can be defined in a netCDF file with the following parameters:

  <table class="sis">
  <caption>Example of identifiers in netCDF name space</caption>
  <tr><th>Name in netCDF namespace</th>                           <th>Name in default namespace (EPSG)</th></tr>
  <tr><td><code>"NetCDF:semi_major_axis"</code></td>                   <td></td></tr>
  <tr><td><code>"NetCDF:semi_minor_axis"</code></td>                   <td></td></tr>
  <tr><td><code>"NetCDF:latitude_of_projection_origin"</code></td>     <td>Latitude of natural origin</td></tr>
  <tr><td><code>"NetCDF:longitude_of_projection_origin"</code></td>    <td>Longitude of natural origin</td></tr>
  <tr><td><code>"NetCDF:scale_factor_at_projection_origin"</code></td> <td>Scale factor at natural origin</td></tr>
  <tr><td><code>"NetCDF:false_easting"</code></td>                     <td>False easting</td></tr>
  <tr><td><code>"NetCDF:false_northing"</code></td>                    <td>False northing</td></tr>
  </table>

  <h4 id="main-usage-heading5">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.4</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="GEOTIFF">
 <h3>GEOTIFF</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</span>&nbsp;<span class="element-name">GEOTIFF</span></div>
 <div class="block">The authority for identifiers of objects defined by the
  the <a href="https://www.ogc.org/standards/geotiff">GeoTIFF</a> specification.
  This specification identifies some map projections by their own numerical codes.

  <h4 id="main-usage-heading6">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.4</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="PROJ4">
 <h3>PROJ4</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">PROJ4</span></div>
 <div class="block">The authority for identifiers of objects defined by the <a href="https://proj.org/">PROJ</a> project.
  We use the <code>PROJ4</code> name for historical reasons, because those identifiers were defined mostly
  when the project was known as "Proj.4". Starting at PROJ version 6, EPSG identifiers should be used
  instead.

  <h4 id="main-usage-heading7">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.4</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="MAP_INFO">
 <h3>MAP_INFO</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</span>&nbsp;<span class="element-name">MAP_INFO</span></div>
 <div class="block">The authority for identifiers of objects defined by MapInfo.

  <h4 id="main-usage-heading8">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.6</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="S57">
 <h3>S57</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Integer.html" title="class or interface in java.lang" class="external-link">Integer</a>&gt;</span>&nbsp;<span class="element-name">S57</span></div>
 <div class="block">The <cite>IHO transfer standard for digital hydrographic data</cite> specification.

  <h4 id="main-usage-heading9">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../../../../../../../org.apache.sis.referencing/org/apache/sis/referencing/ImmutableIdentifier.html#getAuthority()"><code>ImmutableIdentifier.getAuthority()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.6</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="ISBN">
 <h3>ISBN</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">ISBN</span></div>
 <div class="block">The <cite>International Standard Book Number</cite> (ISBN) defined by ISO-2108.
  The ISO 19115 metadata standard defines a specific attribute for this information,
  but the SIS library handles it like any other identifier.

  <h4 id="main-usage-heading10">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="DefaultCitation.html#getIdentifiers()"><code>DefaultCitation.getIdentifiers()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>See Also:</dt>
 <dd>
 <ul class="tag-list">
 <li><a href="DefaultCitation.html#getISBN()"><code>DefaultCitation.getISBN()</code></a></li>
 </ul>
 </dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="ISSN">
 <h3>ISSN</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="../../../xml/IdentifierSpace.html" title="interface in org.apache.sis.xml">IdentifierSpace</a>&lt;<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&gt;</span>&nbsp;<span class="element-name">ISSN</span></div>
 <div class="block">The <cite>International Standard Serial Number</cite> (ISSN) defined by ISO-3297.
  The ISO 19115 metadata standard defines a specific attribute for this information,
  but the SIS library handles it like any other identifier.

  <h4 id="main-usage-heading11">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="DefaultCitation.html#getIdentifiers()"><code>DefaultCitation.getIdentifiers()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>See Also:</dt>
 <dd>
 <ul class="tag-list">
 <li><a href="DefaultCitation.html#getISSN()"><code>DefaultCitation.getISSN()</code></a></li>
 </ul>
 </dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="SIS">
 <h3>SIS</h3>
 <div class="member-signature"><span class="modifiers">public static final</span>&nbsp;<span class="return-type"><a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a></span>&nbsp;<span class="element-name">SIS</span></div>
 <div class="block">The codespace of objects that are specific to the <a href="https://sis.apache.org/">Apache SIS</a> project.

  <h4 id="main-usage-heading12">Main usage</h4>
  This value can be returned by:
  <ul>
    <li><a href="../quality/DefaultConformanceResult.html#getSpecification()"><code>DefaultConformanceResult.getSpecification()</code></a></li>
  </ul></div>
 <dl class="notes">
 <dt>Since:</dt>
 <dd>0.4</dd>
 </dl>
 </section>
 </li>
 </ul>
 </section>
 </li>
 <!-- ============ METHOD DETAIL ========== -->
 <li>
 <section class="method-details" id="method-detail">
 <h2>Method Details</h2>
 <ul class="member-list">
 <li>
 <section class="detail" id="values()">
 <h3>values</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type"><a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>[]</span>&nbsp;<span class="element-name">values</span>()</div>
 <div class="block">Returns the values declared in this <code>Citations</code> class.</div>
 <dl class="notes">
 <dt>Returns:</dt>
 <dd>the value declared in this <code>Citations</code> class.</dd>
 <dt>Since:</dt>
 <dd>1.0</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="fromName(java.lang.String)">
 <h3>fromName</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type"><a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a></span>&nbsp;<span class="element-name">fromName</span><wbr><span class="parameters">(<a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;identifier)</span></div>
 <div class="block">Returns a citation of the given identifier. The method makes the following choice:

  <ul>
    <li>If the given title is <code>null</code> or empty (ignoring spaces), then this method returns <code>null</code>.</li>
    <li>Otherwise if the given string matches an <a href="DefaultCitation.html#getIdentifiers()">identifier</a> of one of
        the predefined constants (<a href="#EPSG"><code>EPSG</code></a>, <a href="#GEOTIFF"><code>GEOTIFF</code></a>, <i>etc.</i>), then that constant is returned.</li>
    <li>Otherwise, a new citation is created with the specified name as the title.</li>
  </ul></div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>identifier</code> - the citation title (or alternate title), or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd>a citation using the specified name, or <code>null</code> if the given title is null or empty.</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="titleMatches(org.opengis.metadata.citation.Citation,org.opengis.metadata.citation.Citation)">
 <h3>titleMatches</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">titleMatches</span><wbr><span class="parameters">(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c1,
  <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c2)</span></div>
 <div class="block">Returns <code>true</code> if at least one <a href="DefaultCitation.html#getTitle()">title</a> or
  <a href="DefaultCitation.html#getAlternateTitles()">alternate title</a> in <code>c1</code> is leniently
  equal to a title or alternate title in <code>c2</code>. The comparison is case-insensitive
  and ignores every character which is not a <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isLetterOrDigit(int)" title="class or interface in java.lang" class="external-link">letter or a digit</a>. The titles ordering is not significant.</div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>c1</code> - the first citation to compare, or <code>null</code>.</dd>
 <dd><code>c2</code> - the second citation to compare, or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd><code>true</code> if both arguments are non-null, and at least one title or alternate title matches.</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="titleMatches(org.opengis.metadata.citation.Citation,java.lang.String)">
 <h3>titleMatches</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">titleMatches</span><wbr><span class="parameters">(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation,
  <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;title)</span></div>
 <div class="block">Returns <code>true</code> if the <a href="DefaultCitation.html#getTitle()">title</a> or any
  <a href="DefaultCitation.html#getAlternateTitles()">alternate title</a> in the given citation
  matches the given string. The comparison is case-insensitive and ignores every character
  which is not a <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isLetterOrDigit(int)" title="class or interface in java.lang" class="external-link">letter or a digit</a>.</div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>citation</code> - the citation to check for, or <code>null</code>.</dd>
 <dd><code>title</code> - the title or alternate title to compare, or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd><code>true</code> if both arguments are non-null, and the title or an alternate
          title matches the given string.</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="identifierMatches(org.opengis.metadata.citation.Citation,org.opengis.metadata.citation.Citation)">
 <h3>identifierMatches</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">identifierMatches</span><wbr><span class="parameters">(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c1,
  <a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;c2)</span></div>
 <div class="block">Returns <code>true</code> if at least one <a href="DefaultCitation.html#getIdentifiers()">identifier</a>
  <a href="../DefaultIdentifier.html#getCode()">code</a> in <code>c1</code> is equal to an identifier code in
  <code>c2</code>. <a href="../DefaultIdentifier.html#getCodeSpace()">Code spaces</a> are compared only if
  provided in the two identifiers being compared. Comparisons are case-insensitive and ignores
  every character which is not a <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isLetterOrDigit(int)" title="class or interface in java.lang" class="external-link">letter or a digit</a>.
  The identifier ordering is not significant.

  <p>If (and <em>only</em> if) the citations do not contains any identifier, then this method
  fallback on titles comparison using the <a href="#titleMatches(org.opengis.metadata.citation.Citation,org.opengis.metadata.citation.Citation)"><code>titleMatches</code></a>
  method. This fallback exists for compatibility with client codes using the citation
  <a href="DefaultCitation.html#getTitle()">titles</a> without identifiers.</p></div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>c1</code> - the first citation to compare, or <code>null</code>.</dd>
 <dd><code>c2</code> - the second citation to compare, or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd><code>true</code> if both arguments are non-null, and at least one identifier matches.</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="identifierMatches(org.opengis.metadata.citation.Citation,java.lang.String)">
 <h3>identifierMatches</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type">boolean</span>&nbsp;<span class="element-name">identifierMatches</span><wbr><span class="parameters">(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation,
  <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a>&nbsp;identifier)</span></div>
 <div class="block">Returns <code>true</code> if at least one <a href="DefaultCitation.html#getIdentifiers()">identifier</a>
  in the given citation have a <a href="../DefaultIdentifier.html#getCode()">code</a> matching the given
  string. The comparison is case-insensitive and ignores every character which is not a
  <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isLetterOrDigit(int)" title="class or interface in java.lang" class="external-link">letter or a digit</a>.

  <p>If (and <em>only</em> if) the citation does not contain any identifier, then this method
  fallback on titles comparison using the <a href="#titleMatches(org.opengis.metadata.citation.Citation,java.lang.String)"><code>titleMatches</code></a>
  method. This fallback exists for compatibility with citations using
  <a href="DefaultCitation.html#getTitle()">title</a> and
  <a href="DefaultCitation.html#getAlternateTitles()">alternate titles</a> (often abbreviations)
  without identifiers.</p></div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>citation</code> - the citation to check for, or <code>null</code>.</dd>
 <dd><code>identifier</code> - the identifier to compare, or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd><code>true</code> if both arguments are non-null, and an identifier matches the given string.</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="getIdentifier(org.opengis.metadata.citation.Citation)">
 <h3>getIdentifier</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type"><a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></span>&nbsp;<span class="element-name">getIdentifier</span><wbr><span class="parameters">(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation)</span></div>
 <div class="block">Infers an identifier from the given citation, or returns <code>null</code> if no identifier has been found.
  This method is useful for extracting a short designation of an authority (e.g. <code>"EPSG"</code>)
  for display purpose. This method performs the following choices:

  <ul class="verbose">
    <li>If the given citation is <code>null</code>, then this method returns <code>null</code>.</li>
    <li>Otherwise if the collection of <a href="DefaultCitation.html#getIdentifiers()">citation identifiers</a>
        contains at least one non-<a href="../../../../../../../org.apache.sis.util/org/apache/sis/util/Deprecable.html#isDeprecated()">deprecated</a>
        identifier, then:
      <ul>
        <li>If the <var>codespace</var> (if any) and the <var>code</var> of at least one non-deprecated identifier
            are <a href="../../../../../../../org.apache.sis.util/org/apache/sis/util/CharSequences.html#isUnicodeIdentifier(java.lang.CharSequence)">valid Unicode identifiers</a>
            (with relaxed rules regarding the code), then the <strong>first</strong> of those identifiers
            is returned in a <code>"[codespace:]code"</code> format. If a <var>codespace</var> exists,
            then the above restriction about the <var>code</var> is relaxed in two ways:
          <ul>
            <li>The code is allowed to start with a
                Unicode identifier <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isUnicodeIdentifierPart(int)" title="class or interface in java.lang" class="external-link">part</a>
                (not necessarily <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isUnicodeIdentifierStart(int)" title="class or interface in java.lang" class="external-link">start</a>)
                since the <var>codespace</var> already provides the start character.</li>
            <li>The code is allowed to contain some other characters (currently <code>'.'</code> and <code>'-'</code>)
                commonly found in identifiers in the codespace managed by various authorities.</li>
          </ul>
        </li>
        <li>Otherwise the first non-empty and non-deprecated identifier is returned in a
            <code>"[codespace:]code"</code> format, despite not being a valid Unicode identifier.</li>
      </ul>
    </li>
    <li>Otherwise if the citation contains at least one non-deprecated <a href="DefaultCitation.html#getTitle()">title</a>
        or <a href="DefaultCitation.html#getAlternateTitles()">alternate title</a>, then:
      <ul>
        <li>If at least one non-deprecated title is a <a href="../../../../../../../org.apache.sis.util/org/apache/sis/util/CharSequences.html#isUnicodeIdentifier(java.lang.CharSequence)">unicode identifier</a>, then the <strong>first</strong> of those titles is returned.</li>
        <li>Otherwise the first non-empty and non-deprecated title is returned,
            despite not being a valid Unicode identifier.</li>
      </ul>
    </li>
    <li>Otherwise this method returns <code>null</code>.</li>
  </ul>

  <div class="note"><b>Note:</b>
  This method searches in alternate titles as a fallback because ISO specification said
  that those titles are often used for abbreviations. However, titles are never searched
  if the given citation contains at least one non-empty and non-deprecated identifier.</div>

  This method ignores leading and trailing <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isWhitespace(int)" title="class or interface in java.lang" class="external-link">whitespaces</a>
  in every character sequences. Null or empty trimmed character sequences are ignored.
  This method does <em>not</em> remove <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isIdentifierIgnorable(int)" title="class or interface in java.lang" class="external-link">ignorable characters</a>.
  The result is a string which is <em>likely</em>, but not guaranteed, to be a valid XML or Unicode identifier.
  The returned string is useful when an "identifier-like" string is desired for display or information purpose,
  but does not need to be a strictly valid identifier.</div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>citation</code> - the citation for which to get the identifier, or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd>a non-empty identifier for the given citation without leading or trailing whitespaces,
          or <code>null</code> if the given citation is null or does not declare any identifier or title.</dd>
 </dl>
 </section>
 </li>
 <li>
 <section class="detail" id="toCodeSpace(org.opengis.metadata.citation.Citation)">
 <h3>toCodeSpace</h3>
 <div class="member-signature"><span class="modifiers">public static</span>&nbsp;<span class="return-type"><a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html" title="class or interface in java.lang" class="external-link">String</a></span>&nbsp;<span class="element-name">toCodeSpace</span><wbr><span class="parameters">(<a href="http://www.geoapi.org/3.0/javadoc/org.opengis.geoapi/org/opengis/metadata/citation/Citation.html" title="class or interface in org.opengis.metadata.citation" class="external-link">Citation</a>&nbsp;citation)</span></div>
 <div class="block">Infers a code space from the given citation, or returns <code>null</code> if none.
  This method is useful for extracting a short designation of an authority (e.g. <code>"EPSG"</code>)
  for processing purpose. This method performs the following actions:

  <ul class="verbose">
    <li>If the given citation is an instance of <code>IdentifierSpace</code>,
        returns <a href="../../../xml/IdentifierSpace.html#getName()"><code>IdentifierSpace.getName()</code></a>.</li>
    <li>Otherwise, performs the same work than <a href="#getIdentifier(org.opengis.metadata.citation.Citation)"><code>getIdentifier(Citation)</code></a> except that <code>'_'</code>
        is used instead of <a href="../../../util/iso/DefaultNameSpace.html#DEFAULT_SEPARATOR"><code>':'</code></a>
        as the separator between the codespace and the code.</li>
    <li>If the result of above method call is <code>null</code> or is not a
        <a href="../../../../../../../org.apache.sis.util/org/apache/sis/util/CharSequences.html#isUnicodeIdentifier(java.lang.CharSequence)">valid Unicode identifier</a>,
        then return <code>null</code>.</li>
    <li>Otherwise remove the <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Character.html#isIdentifierIgnorable(int)" title="class or interface in java.lang" class="external-link">ignorable characters</a>,
        if any, and returns the result.</li>
  </ul>

  Examples of ignorable identifier characters are <cite>zero width space</cite> or <cite>word joiner</cite>.
  Those characters are illegal in XML identifiers, and should therefore be removed if the Unicode identifier
  may also be used as XML identifier.

  <p>If non-null, the result is suitable for use as a XML identifier except for a few uncommon characters.</p>

  <h4 id="compatibility-note-heading1">Compatibility note</h4>
  the following characters are invalid in XML identifiers. However, since they are valid in Unicode identifiers,
  they could be included in the string returned by this method:
  <ul>
    <li><code>µ</code></li>
    <li><code>ª</code> (feminine ordinal indicator)</li>
    <li><code>º</code> (masculine ordinal indicator)</li>
    <li><code>⁔</code></li>
  </ul></div>
 <dl class="notes">
 <dt>Parameters:</dt>
 <dd><code>citation</code> - the citation for which to infer the code space, or <code>null</code>.</dd>
 <dt>Returns:</dt>
 <dd>a non-empty code space for the given citation without leading or trailing whitespaces,
          or <code>null</code> if the given citation is null or does not have any Unicode identifier or title.</dd>
 <dt>Since:</dt>
 <dd>1.0</dd>
 </dl>
 </section>
 </li>
 </ul>
 </section>
 </li>
 </ul>
 </section>
 <!-- ========= END OF CLASS DATA ========= -->
 </main>
 </div>
 </div>
 </body>
 </html>