That's correct, for example:

You just bought some textures for Paradies Hair

Runtime - Libraries - Pose - "Texture Set II for Paradise Hair"

You could rename it:

Runtime - Libraries - Pose - "MAT - Additional Textures for Paradise Hair" or something similar (as long as there isn't another file with the same name.

The higher level directories, I would not touch as thefixer states. Otherwise you WILL be in a world of hurt. Sorry if I didn't make myself clearer