add new option available in configuration
diff --git a/src/site/apt/configuration.apt b/src/site/apt/configuration.apt
index a35162e..1eaa661 100644
--- a/src/site/apt/configuration.apt
+++ b/src/site/apt/configuration.apt
@@ -237,6 +237,8 @@
 
   * ldap.config.groups.use.rolename=true/false will create groups in ldap with default role if no group<->role mapping found (default false)
 
+  * ldap.config.user.attribute= attribute name to use for user (default uid=)
+
 ** User Manager Implementation(s) to use
 
   * user.manager.impl=cached (since 1.4-M4: Archiva support more than one value comma separated)