Hi Marion

I'm only guessing here so I invite other thoughts

An example:
Partner opens 1S
RHO overcalls 1H insufficient

Your 2S is normally 6-9 but you could have:
Condone the IB and bid 2S is 6-7
Not condone the IB and bid 2S is 8-9

Note the lawbook says "the Regulation Authority MAY disallow..."
In the absence of any explicit confirmation in the Manual (which there isn't in the 2020 NZB Manual) it can be assumed it IS allowed

The 2S bid here should be alerted as the range is unusual 

cheers
Nick

PS try posting your question about Laws 28/29 again without the / in the title (unless you have found the answer elsewhere )

Hi Giles

"Prior agreement by a partnership to vary its understanding during the auction
or play following a question asked, a response to a question or an irregularity
committed by its own side is prohibited."

I can't think of a situation where this might happen

If an irregularity is condoned then it becomes legal (Law 16 A 1 (a)) so the above is not applicable

Otherwise there is usually restrictions on one (if not both) partners of the offending side so again not applicable

The only possibility would be a situation "where the bidding (or play) continues normally"
In which case the understandings could be altered but why bother??
You have chosen what you believe is the most useful one so would you really want to change it to an inferior one in this situation?

I invite anyone out there to tell me I'm missing something 

From the definition page at the start of the Law book, an irregularity is "a deviation from correct procedure inclusive of, but not limited to, those which involve an infraction by a player."

Just because the opponents accept an irregularity, doesn't mean that it is no longer an irregularity. Just because the opponents don't accept an irregularity doesn't mean that it is no longer an irregularity. There are a few relevant laws for the general principles here (I've listed them below):

LAW10 -ASSESSMENT OF RECTIFICATION
C.Choice after Irregularity
"Subject to Law 16C2, after rectification of an infraction it is appropriate for the offenders to make any call or play advantageous to their side, even though they thereby appear to profit throughtheir own infraction (but see Laws 27 and 72C).".

Logic dictates we look at each of these:

LAW27 –INSUFFICIENT BID

D.Non-offending Side DamagedIf following the application of B1 the Director judges at the end of the play that without assistance gained through the infraction the outcome of the board could well have been different, and in consequence the non-offending side is damaged (see Law 12B1), he shall award an adjusted score. In his adjustment he should seek to recover as nearly as possible the probable outcome of the board had the insufficient bid not occurred.

And

LAW72 -GENERAL PRINCIPLES

C.Awareness of Potential DamageIf the Director determines that an offender could have been aware at the time of his irregularity that it could well damage the non-offending side, he shall require the auction and play to continue (if not completed). At the conclusion of play the Director awards an adjusted score if he considers the offending side has gained an advantage through the irregularity.

But simply put, you can't have two sets of agreements for the same auction - one with an infraction from your side and one without.

What I mean by this is that you can't have the sequence:
(1C) 2C
be a cue bid, but the sequence:
(1C) "is your 1C natural?" 2C
be natural.

This would be an infraction of law 73 B 1
Partners shall not communicate by means such as the manner in which calls or plays are made, extraneous remarks or gestures, questions asked or not asked, or alerts and explanations given or not given.

Or, you can't play different systems if the auction goes:

(1S) 1H -> 2H
and
(1S) 2H

You don't get the benefit of this. Otherwise you could have a range of system notes for when you make insufficient bids, and a whole other set of agreements for when you don't.

Thanks Guys, really appreciate your input.

Thanks,

Maron

Of course its highly illegal to deliberately infringe (Law 72B1) [that law uses the words "must not"]

If anyone maintained they have such an agreement just in case they infringed accidentally (with no intention to ever infringe deliberately)  I would never believe them

And they would be likely breaking Law 73B2 as well (secret agreement) and that law uses the words "gravest possible offence")