[Whistle]

On an Australian WWI soldier's Attestation Papers I've come across a couple of classification terms, which, while I can sort of "guess" what they mean, I would like to know their proper meaning.

Both terms below were given by a medical review board.

The first is B 1 a 4 - my assumption is being unfit for active duty?
The second is A 3 - fit for active duty?

Thanks for any help.