A .pk3 is basically a .zip (with just blah.zip renamed to blah.pk3) containing 4 folders:
- MAPS
- LEVELSHOTS
- SCRIPTS
- TEXTURES
There might as well be a SOUNDS folder to be included, in case you used custom soundfiles.
MAPS contains the .bsp you get after compiling the .map you made with your radiant contains the .tga of the minimap might contain also a folder with some pics starting with "lm_ " or similar... in case you have used 'lightstyles'/flashing lights\\ LEVELSHOTS contains the .tga/.jpg of your levelshot, the picture that shows up during loading\\ SCRIPTS contains the .shader and the .arena files. and the q3map2_<mapname>.shader for the flashing light, in case you have used any\\ TEXTURES contains the textures you used, in case you do not just use standard urt textures but own ones\\
{ map "ut4_ramelle" longname "Ramelle" type "ut_ffa ut_team ut_survivor ut_ftl ut_cah ut_ctf ut_bomb" }
longname is what shows up ingame in the vote menu
stv's original DSWP Forum Topic http://www.dswp.de/old/mapping/mapping-pk3-t793.html