RMB1

I do not understand. If defender deliberately puts a card on the table (face up) it is played and can not be changed.

Is Stayman normally "promisary"? Does tradition Stayman (various strengths with 4 card major or weak with clubs) count as "promisary"? The problem you describe is best dealt with by checking your opponents convention card at the start of the round and agreeing with partner whether the opponents' Stayman counts as promisory.

If he took the card out of his hand and placed it on the table, it is played - no option to change - there is no "mechanical error" for played cards.

Whether partner accepts or not, and that he chose to do so, is authorised - Law 16A1(c) "arising from the legal procedures authorized in these laws".

There was some measure of agreement soon after the 2006 alerting rules came into force that Lightner doubles were still alertable. We think the L&E thought that they had made them not alertable, but had not succeeded. I think players are expected to ask about doubles of (what appears to be) the final (high level) contract. Over the next few months there is work on revision of the EBU regulations - they may address this. cute!

Because the partnership is not "varying its understanding"? (I am not disagreeing, just seeking to understand)

See Understandings over insufficient bids. Is this in the ABF? Is there an ABF election under Law 40B3?

The law seems clear - Law 62D. Law 62D2 does not apply. Law 62D1 says the revoke (even if established) is corrected - offending side make the last two tricks.

encrypted carding methods There is no restriction on encrypted bidding in the EBU.

The IT people managing this sort of thing will ask for as long as they can get - if something goes wrong it may take another 24 hours to fix it - so if the client organisation can give them a weekend then they will take it. Probably start at 6pm on Friday and finish by midnight.

Not much. I would not adjust. I suspect that both North and South knew that although there was no agreement, 2♦ would either be natural or a transfer. I would like them both to have explained that, although it may be the opponents understood that anyway. I believe that South would bid 2♦ with that agreement understanding, content to play 2♦ undoubled. Similarly North can pass even if 2♦ might be a transfer (for the reason he gave).

In the South-West there is a saying - don't take three bites a cherry once september is out - but I can't do the accent <_< I think the answer to the original questions is "bites at the cherry subsequent to the first" If there was bridge question somewhere - sorry - no idea

I can find EBU Orange Book 7 B 7 (It is implicit that the calls should remain in place before that.) Knocking a bidding card on the floor (even accidentally) is contrary to this regulation. As previously, I am surprised that you want to rule differently. If the only bid the OP made at that turn was 2♠, I am not going to rule that the opponents are stuck with believing it was 2♥ (during the auction).

We take as fact that you bid 2♠ The ruling is easy if this bid was changed to 2♥ (in the sense of Law 25) by knocking away the 2♠ card - apply Law 25B1 - the auction stands with the contract played in 2♥X. But this requires the call of 2♥ to be a call - to have been made - and this requires (EBU bidding regulations) apparent intent. Again, we take it as fact that the 2♠ card was knocked away accidentally and (if any one had observed it) there was no intent apparent. I rule on the basis that there was no change of call - the knocking away of the 2♠ card was a misleading "gesture" that misled the rest of the table to think you had opened 2♥. The auction stands with the 2♠ bidding card restored to the table, with the contract played in 2♠X. If this result is favourable to you, I adjust to a normal result of opponents bidding over a weak 2♠ opening. We can argue if this is Law 73F - otherwise I will use Law 12A1.

Yes. Probably. Yes. No.

It is not a law but a regulation. The law allows regulators to make such a regulation. Law 40B3 I agree it is silly* to prevent a non-offending side from developing understanding about whether and how it will bid when accepting/not accepting an insufficient bid (or other irregularity). * if you prefer: unwise / misguided / against the spirit of the game / impossible to implement

If they can play a HUM in first position, can you play a HUM in second position where 1D/1H/1S are natural but could be less than opening values? Are the regulations for this event available on-line?

I am no expert on these methods - but can't you play 3S = stopper ask or clubs ?

I agree, other rulings were possible. So what I learn is not to make rash statements about what rulings are possible.

I did not intend to say that. I had not made up my mind at the time. Sorry for any confusion. All I meant to say (before consulting) that the only issue was whether pass was a LA. I was trying to address a tangential issue (whether extra boards could become necessary) and saying that there were only really two possible rulings - result stands or the result of 5SXX (which both sides had told me was 11 tricks). . (But I don't want this to turn into a debate like the current "pleb"-gate in british politics.)

At multi-session / multi-section event a year or two ago, there was a pair using UI in much this sort of way: asking "leading" questions and getting the right lead. Sometimes the TD was called but usually there was no damage - sometimes the TD did warn them for asking the questions in the way they did. But then they would move to up and down the field to a different section and there would be new TDs - more warnings were given but no procedural penalties - until eventually there were two occurrences in the same 8-board match/round - the same TD was called and re-called and adjustments were assigned. I think the message is - yes, you should call the TD - the pair may have already been warned and the TD will now penalise them.

West was asked why they bid 6♥: "We were 20IMPs up [at the start of the stanza] and these boards were going OK. 5S redoubled [making] could win them the match. I had no tricks. I would have passed the double [without the redouble]."

To me, this suggests that RHO has a take-out double of something shown by the redouble, probably takeout of clubs. This suggests values and that 2♦ is not single-suited. To that extent, the comment suggests bidding a major over playing in ♦.

A bidding box regulation that says bidding cards are picked up at some set time - the end of the auction, the end of the auction period, or whatever.

I have noticed this twice. Years ago, partner lead fourth rather than the "systemic" third-best 8 or 9. We agreed at the end of the hand that we could do that and our opponent thought that was a normal agreement. (Nevertheless, I noted the exception on our convention card because I am a nerd.) Earlier this week a different partner lead a "systemic" third-best 8 and it cost a trick, a game swing, and led to a tie and play-off, which we lost ...