This is the real body of the zone file, it sets where doors are and what state they're in, what mobs load, objects, who to equip, locked chests, rare loads etc. The other files are like the ingredients for your zone, the zone file puts them all together.
# Note on
For mobs or objects, simply substitute a negative number for a positive number to make the max-exist affect the max number in the room rather than in the zone. That is, if you always want 3 (and no more) of the mob in that room, use -3. It will supercede the zone count, so you could have more in a room than you allow in the zone. So a negative max-exist takes precedence over a positive one. It makes sense, I promise!
If flags, maxload