My partnership is quite happy to open 1NT with all hands which lies in the range 15-17(may even be a great 14 sometimes with lots of tenaces) which will have predictable rebid problems.......4333,4432 is obvious......can easily be 5422 even with 2 small doubletons unless it is 5-4 in the majors...5431 with a small singleton only without 4 card spade( a genuine rebid problem then,what's ur rebid after p responded 1 hearts to ur 1 minor opening if u have 1=3=4=5,1=3=5=4,3=1=4=5,1=3=5=4,well one exception is there......we play 3 card raise to 1 major respone to one minor only in case of a 12-15 hcp unbalanced hand,we have methods so that partner can enquire about the degree of support before proceeding.....so some 5431 with 15 hcp,we wont open 1NT,but with 16/17 hcp,we must)...& finally 6332..without a 6 card suit which is too weak to attract me(or my p) to rebid that suit...with 6 spades,however weak it might be,we generally tend to rebid 2 spade,but we are allowed to use our judgement based on the nature of scattering of values....but not with any other weak 6 card suit..so our 1NT opening can contain even a 6 card Major(we can show a 5 or 6 card major in response to our "staymannish" 2 Club enquiry only if we're in the higher zone(17 or good 16,but with 15 hcp,& a weak suit we may respond to "stayman" treating it as 4 card,although partner will know it can be 5 or rarely,but can even be a 6 card major suit with 15 hcp).Actually we like the very narrow range of 1NT opening very much......only this opening bid limits our hand within a quite narrow range & describes the balanced,semi-balanced or quasi-balanced nature of our hand straight away...... We know this is Alertable & we DO alert our 1NT opening......but does this rule says it is illegel????can anyone explain?