2NT
This bid indicates that the bidder has a balanced distribution of suits and a very specific number of High Card Points.
The suit distribution of the hand can be in either of the following three patterns5, 3, 3, 2 In any order
or
4, 3, 3, 3 In any order
or
4, 4, 3, 2 In any suit order
However the point count is different and depends on whether the bidder is responding or opening 2NT.
As a responder in both ACOL and Standard American 2NT means 10 -12 HCP
As opener in Standard American 2NT is 20-22 HCP
As opener in ACOL 2NT is 20-22 HCP