Definition: Structural Object Class
A structural object class is one of the primary object class types. A structural object class is special in that it defines the core type for any entry that contains it. An entry must have exactly one structural class (although that structural class may inherit from other structural or abstract classes).
The structural object class for an entry may be used by other schema elements for defining constraints on directory data. It may be used by a name form definition to control the attribute(s) used in the RDN for the entry, and in turn by a DIT structure rule to control the types of parent entries that it may have. The structural object class may also be used by a DIT content rule to control the set of auxiliary classes and required, allowed, and prohibited attribute types for the entry.