Maps:

The Maps bibliographic format specification is used for all types of printed, electronic, manuscript, and microform cartographic materials, including sheet maps, atlases, and globes.  Material may be monographic or serial in nature.  The designator code MP is often used in written MARC documentation for this material type.

A record created using the MP specifications is identified when Leader/06 (Type of record) contains code e (Cartographic material) or f (Manuscript cartographic material).

The Maps definition of field 006/01-17 and field 008/18-34 is used when the above condition exists.  See 006 and 008:  Maps for codes and character position descriptions.