CardState vs ZONE confusing code?

[muyufan]

I see below code in GameState.ts:
export type CardState = 'DECK' | 'HAND' | 'OTHERS';
but, actully, HS does not have card state like this, according to:
https://hearthsim.info/docs/gamestate-protocol/

DECK, HAND are actully ZONE, what is OTHERS?, thre is also no PLAY zone in GameState.ts: which is most importent battlefield ZONE

maybe I'm still new to here, but it's kind of confusing code for me.