Each book in the catalog has some information like this:

The letters in parentheses are the code for that book in our catalog—you only need to use this if you’re ordering through the mail. The other codes are about the format of the book:

• Size:
  S = small (less than 5x8 inches)
  M = medium (a common size, about 5x8 inches, aka “digest size”)
  L = large (bigger than that)
  MS = “medium square” (a common size, about 6x6 inches)
  
• Cover:
  SPC = screenprinted cover (a.k.a. silkscreen)
  LPC = letterpress printed cover
  LGC = lithograph printed cover
  CPC = cut paper cover (one color pasted over another)
  HCC = hand-colored cover (pencils, marker, linocut, etc.)
  FCC = full color cover (commercially printed)
  
• Binding:
  TB = threadbound (hand-sewn)
  SB = squarebound (commercial paperback)
  or if not otherwise specified, it’s stapled
  
• Interior:
  CI = color interior