Playing with a friend who is not a regular partner, the following auction and problem arose.
Partner opened a strong 2NT. Playing Stayman, with 4450 pattern, I trooted out Three Clubs, played as regular old-fashioned Stayman. Her rebid was Three Hearts.
Being not too familiar with old-fashioned Stayman these days, but with slam interest, I decided to cuebid Three Spades, believing that this must be a cuebid in context. Partner bid Three No Trump, causing me grave concern. The auction broke down after this, and we ended up in Six Hearts, needing a diamond hook to work (it did not) and for an intrafinesse in trumps to result in only one trump loser (hearts split 4-1 the bad way). So, a disaster.
But, the first five bids gave me a thought. I kind of like the idea that Three Spades by me, in this sequence, using these methods, should be a shortness slam move. Partner's 3NT call, then, would ask for the shortness (I would bid Four Hearts to flag spade shortness).
That seems like a relatively easy concept. You might want to add this IF you play old-fashioned Stayman after a 2NT opening.
! = shortness slam try, hearts agreed
* = asking for shortness
But, it could get even more complete. Suppose, for instance, that Three Spades is instead a relay to 3NT. In other words, Three Spades is natural. That seems really easy to remember.
If that is the case, then 3NT would have no particular meaning. For that matter, calls above 3NT would have no particular meaning. If Responder had a hand with four spades and a minor and slam interest, he could first bid Three Spades to check on a fit and then, if opener bids 3NT, show the minor. That saves space when the major fit exists.
Using that more natural approach, Responder's 4C and 4D would be immediate shortness bids. 3NT could be "spades or general slam bump," with Four Clubs asking for clarification, Four Diamonds showing general but Four Hearts showing spade shortness:
3S = natural
3NT = hearts agreed, spade shortness of no shortness (4C asks; 4D = general, 4H = short spade)
4C = hearts agreed, short club
4D = hearts agreed, short diamond
This alternative has the downside of wrong-siding spade contracts, but it enhances all slam sequences when hearts are agreed or when spades end up agreed.
Some food for thought, maybe.