The Object Class Description format is described in RFC 4512, section 4.1.1. The definition is as follows:
ObjectClassDescription = LPAREN WSP numericoid ; object identifier [ SP "NAME" SP qdescrs ] ; short names (descriptors) [ SP "DESC" SP qdstring ] ; description [ SP "OBSOLETE" ] ; not active [ SP "SUP" SP oids ] ; superior object classes [ SP kind ] ; kind of class [ SP "MUST" SP oids ] ; attribute types [ SP "MAY" SP oids ] ; attribute types extensions WSP RPAREN kind = "ABSTRACT" / "STRUCTURAL" / "AUXILIARY"