[pescetom]

 jillybean, on 2024-September-12, 15:33, said:

The answer is of course, YES, and I whack the alert card on the table.
Players assume this is a regular negative double, even when I explain it as "denying FOUR spades"

Much like Support Double, which I alert whether Double or any other call is made, getting odd looks - partly because it is not mainstream here but also from a number of "oh yes, we play that too" surprises ("well alert it then, please").

[jillybean]

I’m not certain if any double in ACBL needs an alert.
It may be that “all doubles are self alerting”

[blackshoe]

"All doubles are self alerting"? No. Not in the ACBL. Read the regulation.

[jillybean]

Doubles
Alert a double of an Artificial Bid that asks for the doubled suit to not be led, or that asks for a
specific suit to be led that is not the doubled strain. Otherwise do not alert a double of 3NT or
higher. Alert a double below 3NT except as listed below.
Do NOT Alert the following doubles:
After an Opening Bid
1. After a Natural or Quasi-Natural suit Opening at any level, a Takeout Double.
2. After a No Trump Opening Bid, a penalty or card-showing double.
3. After an Artificial Opening Bid, any double.
5
After an Opening Bid and an Overcall
1. After a 1-level suit Opening Bid and a Natural suit overcall, a Negative Double by
Responder.
2. After a 1-level suit Opening and an Artificial overcall, any double by Responder.
3. After a 2-level or higher suit Opening Bid and a Natural suit overcall, a penalty double by
Responder.
4. After a Natural 1NT or 2NT Overcall, a penalty double by Responder. After an Artificial
1NT or 2NT Overcall, any double.
5. After a 1NT or 2NT Opening and an overcall at the two or three level, Negative Doubles,
penalty doubles and card-showing doubles by Responder.
After an Opening Bid and a Response (whether or not there was interference)
1. After a Natural or Quasi-Natural Opening suit Bid and a Natural or Quasi-Natural
Response, a Takeout Double.
2. After an Opening Bid and a Response if either the Opening Bid or the Response is
Artificial, any double.
3. After a Natural Opening, Natural overcall, and Natural 1NT Response, any double.
At Opener’s Rebid and Later
1. All doubles by both sides.

really?

[blackshoe]

Yep.

[mycroft]

It is surprising how few doubles are in fact Alertable since the 2019 change. I know I've been caught out with two of them myself(*) - and I read at least 4 pre-published drafts as well as, you know, directing with the new procedure.

Your "denies 4 spades" "negative" double is explicitly Alertable, of course - as made clear in the example. I will admit that there are a lot of things that are not made clear by that example, because they tied themselves in knots trying (and IMO failing) to define Negative Double the way "everybody" plays it. But that part is explicit.

(*) called the director after the auction/after the hand to say double wasn't Alerted (to protect the opponents), only to find out on reading that it wasn't Alertable.