You want to document your schema extensions.
There are several different ways you can document schema extensions. If you require LDIF files of the schema extensions before you extend the schema, you could use the files themselves as a simple self-documenting system. You can put comments in LDIF files by putting # at the beginning of a line. I personally prefer this option and recommend that any company that needs to extend the schema of their customer's Active Directory should include LDIF files, regardless of whether you use that method to actually extend the schema.
Another fairly easy mechanism for documenting schema extensions is with the SchemaDoc program developed by Microsoft. SchemaDoc is a simple GUI program that lets you document classes and attributes that have already been added to Active Directory. The output for SchemaDoc is XML, which you can then use to create your own management interface for viewing the contents.
SchemaDoc can be downloaded from the following site:
More information on SchemaDoc can be found here:
There are no hard and fast rules for documenting schema extensions. Documenting schema extensions in some fashion, even if rudimentary, should be a requirement of any schema extension process you adopt. If you have the resources and time, you can even develop a much more elaborate documentation system using the web or even an object-modeling system.
RFC 2849 (The LDAP Data Interchange Format (LDIF)Technical Specification)