Reserved for future use.
Reserved for internal use (never appear on the wire).
The mapping from ATTRTYPs A to OID O works as follows:
If A in [0x00000000..0x7FFFFFFF], A maps to O via a prefix table as specified in [MS-DRSR] section 5.16.4 (the OidFromAttid procedure).
If A in [0x80000000..0xBFFFFFFF], let X be the object such that X!msDS-IntId equals A. If X is an attributeSchema object, O is X!attributeID; otherwise X is an classSchema object, and O is X!governsID.
Given an OID O, the schema object X representing the class or attribute identified by O is the object X such that either X!attributeID equals O or X!governsID equals O.