UI: What does asking suggest?
South opens 2D, alerted
West asks what it is
By asking, West has given UI, but what does it suggest?
Is it suggesting values?
Is it suggesting diamonds?
Or is it just wanting to know?
I think a lot of people would naturally ask what it was - does this matter?
(It was a Multi: strong NT opener or weak 2 in a major)

Comments
If West didn't ask, that would also give UI (and probably more UI than they would give by asking – there are plenty of possible reasons for asking but few reasons for not asking).
It is helpful to have, as a partnership, a policy for which call you ask about (that doesn't depend on the contents of your hand) – that minimizes the UI you give when you follow the policy.
This sounds a bit fraught. How, for any of a long list of given situations, would you provide evidence to the TD that you would always ask?
At this point, South has just put down the Stop Card and it should remain there for about 10 seconds during which, as West, we should give at least some vague appearance of thinking. But if the players are likely to think we won't know what the 2D means without asking, there is then an argument that goes that we may have to ask about the 2D bid in order to conceal our level of interest. There again, in a local club where NS are well known to play Multi ....
Barrie Partridge - CTD for Bridge Club Live
It suggests nothing except for those who follow the wrong-headed idea (once widespread in the EBU) that you should only ask if the answer makes a difference to what you do at this turn to call.
An alert tells you there is something you might wish to ask about, and this is particularly so with an opening 2D bid which has so many possible alertable meanings.
My policy used to be "ask about any alerted call, any overcall over or double of 1NT, any non-announced 2-level suit response to 1NT, any 2- or 3-level jump overcall in a new suit, and any call that always requires an alert/announcement but wasn't given one". (Some people use variations on this, like asking about unannounced 2NT calls – doubling after (2NT), P, (P) is a better idea if the range includes 19 than if it doesn't, and this sometimes makes a difference, which is enough to inspire some people to always ask.)
I've since made exceptions for situations where the meaning of the call is indicated by the opponents' system summary (if they provided one).
I am not sure that the double of 1NT should be included, especially if playing in person (but it's been useful online, to hide from partner how long it's taken me to type the explanation of my call over the double and thus reduce UI that might be given that way).
I think the world would be much better if all alertable calls were instead announced.
Whilst it does potentially give extra opportunities for people to be given UI, I think that is far outweighed by:
1) The removal of (most of) the "giving UI if I ask" onus on the opponents
2) A smoother auction
3) If the player doesn't have the hand described, it's obvious.
Yes I know a player doesn't have to have their bid, but it alerts the opponents ot the fact that something fishy may be going on.
But then I live in my own little world of songbirds and flowers. :-)
For a while, I've been wondering whether it would make sense for all calls to be announced as either artificial or natural, and either forcing or nonforcing (plus separate announcements for common artificial calls, like transfers) – this would especially make sense online, where the player's partner can't see the announcement. This would replace the alerting system (in that it would flag up to players which bids it might be helpful to ask about).
That way, there wouldn't be a need to know how a "normal" system worked in order to alert properly – if the auction starts something like 1H "natural, nonforcing", 1S "natural, nonforcing", the opponents will know that something weird is going on even if the opening side didn't know how weird their system was.
There are some problems with this design, mostly related to natural bids that have an unusual range. For example, in my most common partnership, (1NT), 2S is natural and non-forcing – but could be a 5-count with only 5 spades, which is unusual enough that I alert it (most players would expect the spades to be longer and/or stronger).
If the opponent's system summary at the start of the round did not mention 2D opening, then asking suggests nothing. Otherwise it suggests very little - a desire to know/check what 2D is - going to have to ask some time - this is a good time to ask.