Yes, in my response to lamford, I didn't link to the EBU Alert procedure that explains your confusion. Sorry:
So yes, "obviously" to all English and Welsh players, a non-Alerted double of an artificial 2
♣ response is clubs. And frankly, I think that's great!
As an example of "'as close to' is pulling a lot of weight", however, witness the following bits out of the regulations (emphasis mine, and only for reference):
Quote
4B2: Doubles
The rules for alerting doubles are:
(a) Suit bids that show the suit bid: Alert, unless the double is for take-out.
...
(d) Suit bids that do not show the suit bid: Alert, unless the double shows the suit bid.
In 4B2(a) and (d) the word ‘show’ is defined as follows:
‘it is natural, or shows willingness, in the context of the auction, to play in the suit, or it has been followed by two passes’.
...
4C1:The following are considered ‘natural’ for the purposes of alerting and regulation of partnership understandings (see also 3E1 [short minor openings]):
(a) A bid of a suit before the opening bidder’s second turn to call which shows that suit and does not show any other suit. A natural bid before the opening bidder’s second turn to call shows 4+ cards, except for a minimum opening or response in clubs or diamonds which only need show 3+ cards. Bids later in the auction also only need show 3+ cards.
Preference bids, completion of transfer bids and raises may be on shorter suits.
So, I play 1
♠-p-3
♣ as a Limit Fit bid - "Primary club suit worth mentioning, spade support, limitish values." My reading of the above is that - at least arguably - that bid doesn't "show" clubs (it's not natural as it shows spades
as well as clubs, surely I'm never going to play in clubs - okay, 6 or 7 maybe - and has not yet and will not be passed by partner), so again arguably, the only not-Alerted double is one that shows responder's long suit. Which is - counterintuitive?
But, apart from constructed scenarios like this one, the complete double Alerting regulation can in 99.9% of cases be boiled down to "if you double NT for penalty, double suit for takeout if natural and lead-directing if artificial, don't Alert, anything else Alert" (except for the "don't Alert almost all doubles over 3NT" bit). And in 99+% of those even the novices can understand, both what to do and what the opponents are doing - if we're willing to teach them. That's something you can't say about any other Alert Procedure.
When I go to sea, don't fear for me, Fear For The Storm -- Birdie and the Swansong (tSCoSI)