Here’s a decent list of book genres by abbreviation:

A   –  Adult

CB – Chapter Book

CP – cyberpunk

MG – Middle Grade

NA – New Adult

NF – Non-fiction

PB – Picture Book

PR – paranormal romance

R – Romance

SF – science fiction

SFF – Science Fiction & Fantasy

UF – urban fantasy

WF – Women’s Fiction

YA – Young Adult

Need more of an understanding of the differences? Find deeper explanations of the genres at Writer’s Digest.