Well, there are two parts to the regulation: how and when to give a "skip bid warning" (with or without bidding boxes), and how the LHO of a skip bidder is supposed to act. In fact, I've just read the actual regulation (ACBL BoD minute 953-102, in Appendix A to Chapter 12 of the "
ACBL Codification"). It is commonly believed, and frequently ruled by directors (including me) that the warning is "optional". However what the regulation actually says is
Quote
The skip bid warning may not be used to alert partner that a strength-showing bid is being made or not being made. The warning should be used all the time. The tournament director may assess a procedural penalty (Law 90) for failure to comply.
(The emphasis is mine). That last sentence accords with the laws' usage of "should" - that failure to do what one "should" do is an infraction, although one rarely penalized. Nonetheless, TDs frequently rule that use of the stop card is "optional", and players have come to believe it, and some choose not to use it. I have been one. I'm going to have to go back to using it all the time, now.
The other part of the regulation is
Quote
When RHO has announced a skip bid, the player following the skip bidder must wait for a suitable interval (about 10 seconds). In waiting the player's manner must be one that suggests he is an active participant in the auction (the hand should be studied during pause). any obvious display of disinterest is most improper.
Note that this part says the player
must wait. Under the current laws, if he
must wait, and does not, he should receive a PP "more often than not". That doesn't happen, either.
The regulation also says
Quote
Experienced players expected to maintain proper temp whether a skip bid is announced or not.
Poorly edited, but that's what it says.
I've gotten a little sidetracked. What I was trying to say earlier was that a lot of people don't give the warning (which at the time I wrote that I thought was optional), and they don't pause the appropriate amount of time. I think both are down to either ignorance of the regulation, or "I don't care, I'll do what I want". Sometimes both.
If there is a BIT (either fast or slow) the regulation specifies
Quote
When a player acts with undue haste or hesitation, the tournament director may award an adjusted score (Law 16) and/or procedural penalty (Law 90).
There is one caveat in the regulation, applicable to clubs.
Quote
The warning is effective for all ACBL sanctioned events. For sanctioned games at clubs, the club may elect to discourage it's use and require no mandated pause.
(Why do people insist on sticking apostrophes in where they don't belong?)