Platform SDK: Active Directory, ADSI, and Directory Services

Structural, Abstract, and Auxiliary Classes

The objectClassCategory attribute of a classSchema object can have one of the following values which indicates whether the class is structural, abstract, or auxiliary.

Value Description
1 A structural class, which is the only type of class that can have instances in Active Directory.
  • A structural class can be a subclass of an abstract or structural class.
  • A structural class can include any number of auxiliary classes in its definition.
2 An abstract class, which is a template used to derive new abstract, auxiliary, and structural classes.
  • An abstract class can only be a subclass of an abstract class.
  • Abstract classes cannot be instantiated in Active Directory
  • An abstract class can include any number of auxiliary classes in its definition.
3 An auxiliary class, which can be included in the definition of a structural, abstract, or auxiliary class, in which case, the mustContain, systemMustContain, mayContain, and systemMayContain values of the auxiliary class are added to those of the class.
  • An auxiliary class can be a subclass of an abstract or auxiliary class.
  • Auxiliary classes cannot be instantiated in Active Directory.
  • An auxiliary class can include any number of auxiliary classes in its definition.

Do not confuse the objectClassCategory with "object category".