I mean the part of "ORIGINAL SOUNDTRACK"
Certainly not match the official site, since this also uses lowercase formality.
Evidence:
Angel Beats!:
http://key.soundslabel.com/discograp...sl0035/ksl0035
Kanon:
http://key.soundslabel.com/discograp...sl0035/ksl0035
Evidence that defines the name is used in Itunes:
https://itunes.apple.com/jp/album/ri...ck/id784286860