When the 1 club opener after a 1 heart or 1 spade answer
bids 1NT this imay be used to ask about controls in partner's hand. Ace = 2 controls, King = 1 control
The answers are:
1. step: 0-2 controls.
2. step: 3 controls.
3. step: 4 controls.
and so on
Further bids:
A new suit on the 2-level may be used as another asking bid, Theta.
If you bid the major suit partner bid this is Gamma.
A new suit on the 3-level is natural.
Later bids of 4 clubs is Beta!
NB! When the answer hand bid 1NT on 1 club, 2 in a suit may be Alpha.