Your library files (CR2, PP2, PZ2, HR2 etc.) can go in any folder in the appropriate lib. without breaking amything - it's only the OBJ file that must go where the reference says, and textures can be a pain if Poser can't find them (but I stick mine in an item-specific sub-folder of a Textures subfolder of the library subfolder, along with the readme and licence files, and Poser rarely chokes). You can also rename these files freely, as long as the file and its RSR/PNG match.