DefaultObjectCategory is the DistinguishedName of this objectClass or one of its SUP.

The objectCategory property is an indexed property used to increase the efficiency of objectClass searches. If DefaultObjectCategory is not specified when a class is created, the system sets it to the distinguished name (DN) of the classSchema object for this class. If this object will be frequently queried by the value of a superclass rather than the object's own class, you can set DefaultObjectCategory to the DN of the SUP. For example, if you are subclassing a predefined (category 1) class, the best practice is to set DefaultObjectCategory to the same value as the superclass. This enables the standard UI to "find" your subclass.

When an instance of this object class is created, the system sets the objectCategory property of the new instance to the value specified in the DefaultObjectCategory property of its object class.

LDAP Microsoft Active Directory Attribute Definition#

The DefaultObjectCategory AttributeTypes is defined as:

More Information#

There might be more information for this subject on one of the following: