Model/Body configuration - color (and body/top wood types, when available) - neck (and fretboard/inlay/headstock) - pickguard - case - hardware
901 - SM y2d hard tail
CH - Honey Roasted (quilt) on African mahogany body
PM - pau Ferro board with roasted maple neck, and, if I remember correctly, matching headstock
15 - clear pickguard with black pickups
CS - case (this one would be SKB style)
LE - chrome hardware, I don't remember if these all came with pearl buttons or not (normally this would be "CR" for chrome, "BM" for black matte, etc)