/Ut2004/___
          |
          v

/ut2004/Animations
../Benchmark
../Cache
../Demos
../ForceFeedback
../Help
../KarmaData
../Manual
../Maps
../Music
../Prefabs
../Saves
../Screenshots
../Sounds
../Speech
../StaticMeshes
../System
../Textures
../UserMovies
../Web

A map pack has the same structure, with some missing folders that
would elsewise just be empty dirs. Thus, when pasted into /ut2004/,
all files go into their proper folders.. and it JustWorks(TM). Some of
these might appear, because I've ran it and shit..

So.. Like this.

/ucmp1234.zip/

/ucmp1234.zip/Mmaps
../StaticMeshes
../System (not always)
../Textures

And then, you stick the whole thing in /ut2004/, dirs are overwrite,
and the files go right where they belong..