Directory Services

Naming Attributes and Classes

To create a new class or attribute, adhere to the following naming rules:

For example, if the fictitious Fabrikam company extended the schema by adding an attribute for storing a voice-mail identifier, the cn and lDAPDisplayName of the new attribute could be "fabrikam-VoiceMailID".

To qualify for the "Certified for Windows" logo, an application must adhere to these schema naming rules. In addition, the company prefix used in the schema extension names must be registered. For more information about registering the company prefix, see For more information about the certification program, see

If the lDAPDisplayName of an attribute or class is not specified, the system uses the cn to generate one. However, the system algorithm for generating the name may result in name collisions or names that are difficult to read. To avoid these problems, it is recommended that an lDAPDisplayName be explicitly specified for all attributes and classes.

For development and testing purposes, it may be desirable to append a version suffix to the cn and lDAPDisplayName, for example, "fabrikam-VoiceMailID-001". In a distributed development/test environment, a version suffix enables developers to run multiple versions of their software simultaneously. After testing is complete, rename the attribute or class to remove the suffix.

It is not possible to delete defunct versions of a schema extensions, but it is possible to disable them and rename them with obscure names. For more information, see Disabling Existing Classes and Attributes.