Schema object names
Updated: May 1, 2010
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Schema object names
When extending the schema, you need to know how to reference schema objects. Both class and attribute schema objects can be referenced in several ways:
Lightweight Directory Access Protocol (LDAP) display name
LDAP display name
The Active Directory Schema snap-in and other administrative tools display the LDAP display name of objects. Programmers and system administrators use LDAP display names to reference objects programmatically. The LDAP display name typically consists of two or more words combined. When the name consists of multiple words, subsequent words in the name are identified using capitalization. Example LDAP display names are mailAddress and machinePasswordChangeInterval. The LDAP display name is guaranteed to be unique for each object.
The common name is a more readable version of the LDAP display name. The common names of the two attributes used in the previous example are SMTP-Mail-Address and Machine-Password-Change-Interval. Common names are guaranteed to be unique within a container.
An object identifier (also known as OID) is issued by an issuing authority such as the International Organization for Standardization (ISO) or the American National Standards Institute (ANSI). For example, the object identifier for the SMTP-Mail-Address attribute is 1.2.840.1135126.96.36.1996. Every object identifier must be unique. For more information about ISO, see the International Organization for Standardization Web site.
When extending your schema, you can register new object identifiers through Microsoft. For more information, see the Microsoft Web site.
Schema object naming rules
To help standardize schema naming conventions, Microsoft strongly suggests that schema extensions adhere to naming rules for both the LDAP Display Name and the Common Name. To qualify as "Certified for Windows," an application that extends the schema must adhere to these naming rules. For more information, see the Active Directory chapter of the certification program documentation at the Microsoft Web site. See also the Active Directory Programmer's Guide at the Microsoft Web site.
Message queuing aliases
A message queuing alias is an object in Active Directory that can be used to reference queues which might not be listed in Active Directory. For example, a queuing alias can be used to reference a private queue within the context of a distribution list. You can create a queuing alias by using Active Directory Users and Computers. Using queuing aliases provides the following benefits:
When a queuing alias object is deleted, the alias is automatically removed from all distribution lists that reference the alias.
A queue referenced by a queuing alias can be changed without changing the alias.
Queuing aliases can be used to reference a queue not listed in the directory service, including private queues or queues from another organization.
Queuing aliases can be used to send http messages by referencing the destination queue using a direct format name.
A queuing alias object has a single attribute, a format name that references a queue. Queuing aliases can contain public, private, and direct format names. The format name for the queue cannot exceed 255 characters. For more information, see Using Message Queuing.