The BAK0 mesh, with all its heel/toe combinations plus one - that of the original B300 foot - is the same as the BAG0 mesh, but with its texture map shrunk to three-quarters of the texture surface, leaving room for accessory textures to the side. This allows accessories to be re-textured like body meshes. The method isn't new: I've seen several Sailor Moon character meshes that use it, though not as systematically as it's applied here. A better description of this mesh's use will follow when I've made some example screenshots.
Update 12-04-2008: Fixed a mistake in some 02-heels and some UV niggles.
Update 15-03-2009: Vertex fault in SPINE joint found in the higher CBL heels. Fixed BYT waist while I was at it.
Except for the texture maps, the heeled BAK0 meshes are identical to their BAG0 counterparts. Illustrations of how they can be used will follow later. For now, here are the downloads: