Naming Attributes and Classes

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

• Use the same name for both the cn and lDAPDisplayName properties of a new attributeSchema or classSchema object.
• Identify the company with a lower-case prefix in the first section of the name. This prefix can be a DNS name, acronym, or other string that uniquely identifies the company. The prefix ensures that all attributes and classes for a specific company are displayed consecutively when browsing the schema.
• Use a hyphen as the next character after the prefix.
• Specify an attribute or class name that is unique within the company's attributes after the hyphen. This part of the common-name should be descriptive. Do not use illogical names that are meaningless to developers and viewers of the schema.

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 http://msdn.microsoft.com/certification/ad-registration.asp. For more information about the certification program, see http://msdn.microsoft.com/certification.

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.