Statically Linked at Creation#An auxiliary class can be statically linked to an object class when the class is defined, that is, when its classSchema object is added to the schema container. This is the only time that the systemAuxiliaryClass can be used.
After a classSchema object is created, its systemAuxiliaryClass attribute cannot be modified. An auxiliary class that is Statically Linked at Creation can have mandatory (mustHave) and/or optional (mayHave) attributes.
Statically Linked AFTER Creation#Microsoft's page has some confusion or errors. This is what we believe is correct, but is not as Microsoft states.
A privileged user with the permissions required to extend the schema can add or remove auxiliary classes from the auxiliaryClass attribute of an existing classSchema object. Doing so adds or removes the auxiliary class from every existing instance of the object class.
An auxiliary class that is statically linked at this time can have optional attributes, but cannot have mandatory attributes. This is because there may be existing instances of the object class, in which case, adding a new mandatory attribute would create problems.
A privileged user can subsequently remove an auxiliary class from the auxiliaryClass attribute of a classSchema object.
More Information#There might be more information for this subject on one of the following:
- Dynamically Linked Auxiliary Classes
- MAD Determine the Classes Associated With an Entry
- ObjectClass vs ObjectCategory
- StructuralObjectClass Attribute