Mission Pack Forms are the information of certain mission packs that has various sections like "Characters" and "Missions". DYOM Users use Mission Pack Forms to write the information about Mission Pack's Plot, Characters, Spoilers and other stuff on gtaforums.
List of known forms
Plot is a literary term defined as the events that make up a story in mission packs. It describes what happened before the mission pack and sometimes what will happened.
A map is an image that is created by image-creating software and placed in mission-pack threads in gtaforums.
Purpose of the map
The purpose of creating a map is almost the same as in GTA:San Andreas game, to find mission givers, check special places and for other uses. Usually, mission givers can be found in game map, if creator uses a storyline feature. Also, people use map for territories, which gang owns it, similar to original game map.