PHS

[MJN SEIFER]

anybody have any idea what it stands for?

edit: apparently it's explained here, so mystery solved.

I know it stands for Party Hensei System because Barret calls it that in the game,

No he doesn't. When he gives it to you he just says "this is a PHS". I know because for years and many playthroughs I was just calling it "Phone Home Somebody".

It's mentioned somewhere though - either on the tutorial or somewhere else.