z:__debug:some debug/test rooms
     a:__easy:"easy"      - Play these tutorial rooms first
   b:__normal:"normal"    - You can do it..!
c:__difficult:"difficult" - Do not start with these rooms !!
 d:__original:"original"  - The original mapset (early versions)
#z:__debug:some debug/test rooms
#l:larz:Larz' rooms
#z:__debug:some debug/test rooms
y:__hidden:"hidden"
