The data.cpk file found in Persona 5 contains a GMD model folder, Persona 5/data.cpk/model/character. Each folder is categorized by character ID number. See Persona 5/data.cpk/model/character for a full list of ID number with character names and descriptions. 2001 refers to Igor, and several GMD models related to him. The directory also contains folders organizing GAP animations by purpose (field, battle, event).
The below table was automatically generated based on similarities to other directories. Please remove this notice once inaccuracies have been corrected.