Legit companies...

Music:
COCC – Columbia Japan
KICA, KIDA, KICS – King Record (Starchild)
KTCR – Kitty
LACA – Lantis
PICA, PIDA – Pioneer
PCCG – Pony Canyon
TKCA, <2digits>ATC – Tokuma Japan
TYCY – Toshiba-EMI (Futureland)
VICL, VIDL – Victor (also known as JVC)
VPCG – Vap
SVWC – SME Visual Works (also known as Aniplex)

Source:  http://music.3yen.com/category/bootlegs/

Comment on this post if you know of more companies.Thanks!