content/api/user-guide/4.2.1.3-syntaxes.mdtext

Title: 4.2.1.3 - Syntaxes
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# 4.2.1.3 - Syntaxes

The **LdapSyntax** class implements the LDAP **Syntax**s schema objects. A **Syntax** defines constraints applied to the **AttributeType** value. Here is the RFC description of a **Syntax** :

     SyntaxDescription = LPAREN WSP
         numericoid                 ; object identifier
         [ SP "DESC" SP qdstring ]  ; description
         extensions WSP RPAREN      ; extensions

The important part of the **Syntax** is its **OID** which is used in the **AttributeType** and **MatchingRule**.

In order to enforce a **Syntax**, the **LDAP API** is associated with a **SyntaxChecker**, which is a Java class (see the chapter about ApacheDS Schema Elements).

## Methods

The are the two most important methods that you might need:

* getSyntaxChecker() : retreive the associated class that is used to check a syntax
* isHumanReadable() : tells if the AttributeType is a String or a byte[]