Celltags
This page should correctly be named "[Celltags]"; it is wrong due to technical restrictions.
CellTags are a method of marking cells on a map for scripting. The index to the left of the equal sign is a combination of map X/Y coordinates, while the value on the right is the index of an attached tag in the [Tags] section of the map. This can then be used to activate a tag when a unit moves onto the cell, something used extensively in the singleplayer campaign maps.
Normally CellTags are placed (or removed) graphically in a map editor such as FinalSun or FA2sp, so there should be little reason to edit this section, except to entirely remove it.