[zenbiddist]

I have a few simple thoughts on Exclusion which might be relevant to your query:

Exclusion responses
A common treatment: 0, 1, 1+queen, 2, 2+queen, etc

This gets you excessively high sometimes, and therefore you can't afford to use it, undermining the benefit of the convention. Another issue with this type of response structure is that it wastes a lot of space on the 0 and 1 steps when the answer is known to be higher (i.e. from a 2♣ opener).

I prefer just to play simple Roman Keycard style responses to Exclusion for this reason.

Lower void-showing bids
The neatest fix, which doesn't require extensive agreements, is to prioritise void-showing in cue-bidding auctions. Krzysztof Martens' slam bidding book explains this very clearly. In short, if you control bid a suit and then bid it again, you have a void, and the priority of showing it overrides other control bids.

When is it Exclusion?
The other issue that comes up frequently in new partnerships is confusion over when Exclusion applies. In a fresh partnership, I like the simple rule that jumps to game are to play.
Another auction that I have seen create some confusion is a non-jump to 5-bananas in a competitive auction. Example:

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But what would you do with this hand?

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What are the continuations?
I've seen very good pairs miss grand slams because they haven't discussed the follow-up bids. There are probably optimal methods I haven't encountered, but for simplicity I play the same as RKC:
1st non-trump step = Queen ask (unless queen known)
2nd non-trump step = specific king ask
Last train = generic try
Other bids inbetween (rare that they exist) = 3rd round control ask

[Lovera]

For what has been said, indicating the three application conditions, it follows that: the Exclusion bidding is executed as a jump when the partner's bid has not reached game while it is at level in the other two cases. It is important to highlight the concept of "new suit" as a suit never before bidded by the player who has the void that means that between the couple will be bidded at most three suits that allow to start EKB.

[Lovera]

Another situation in a contested (or competitive) bidding is also: S1♣-W(1♦)-N1♠-E(p),3♠-(p)-4♦(=N query for keycards exculding Diamond suit with spade as trump after jump raise) referring its at the case a) as overcalling of the suit of an opponent.

[msjennifer]

(Sir.,to simplify things we consider an unnecessary jump in a new suit as an exclusion Blackwood.(only where it shall not be confused as a splinter bid). In fact ,that is why in Modern Precision the opener never makes a splinter bid .

[Lovera]

This overcalling of the opponent's suit that is carried out in the second round and after an FG by the opener partner always maintains the meaning of having no losers in the bidded suit (that in fact is a void) and can also be read as a splinter bid....who query at the same time.

[pescetom]

msjennifer, on 2019-January-27, 10:04, said:

(Sir.,to simplify things we consider an unnecessary jump in a new suit as an exclusion Blackwood.(only where it shall not be confused as a splinter bid). In fact ,that is why in Modern Precision the opener never makes a splinter bid .

So you're saying that you play 1♣ - 1♠; 3♦ as Exclusion rather than a splinter?
What does 1♣ - 1♠; 4♦ mean?

[Lovera]

It follows, therefore, that when this overcalling (i.e.as in post #63) of a defender's suit is preceded by a forcing jump bidded by the same player who has the void or by his partner, this bidding that is brought to game level must therefore be interpreted like EKB.

[Lovera]

If you go to the bridgeguys.com site where Goldman's "Exclusion Keycard Blackwood" is presented, you will find this: "Notes: The convention of Exclusion Keycard Blackwood is also referred to as Voidwood.
Notes: The photograph of Mr. Robert (Bobby) Goldman is from the year 1982.

Basic Concept
In Exclusion Keycard Blackwood there are only four Keycards. Void suit is not counted. Therefore, only the other 3 Aces and the King of the trump suit count as the four Keycards. This conventional method is initiated:

1.After establishing the trump suit.2.By a jump bid higher than the game level in an unbid suit or3.In a suit bid by the opponents.

The suit of the jump bid is then excluded by partner from any response bids. The answer to the Keycard Asking is completed in the following way:

1st Step: Shows 0 Keycards.2nd Step: Shows 1 Keycard.3rd Step: Shows 2 Keycards.4th Step: Shows 3 Keycards." This presentation of the three application points reinforces my belief that the current convention has resumed that part of Smith regarding hands with special distribution (= with a missing suit). Therefore my indication in post #53 of the publication in the specialized journal "The Bridge World" was aimed at having the indications or considerations of the bidding problems that could have been presented and which can be taken taking into account the current bidding / competitive development without taking into account the response steps that have been changed with the keycards whose indication, if it were possible to have from that source or a similar one, would be useful to continue the discussion, considering more detailed the three conditions of the previous convention (for example in the case c where it was already reached the game level is also included the 3 NT bid).

[nullve]

My partner and I are trying to complete the auction on this deal:

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Is there any reason to believe 4♠ should be Exclusion in this position?

[pescetom]

nullve, on 2019-February-16, 09:08, said:

Is there any reason to believe 4♠ should be Exclusion in this position?

If you play 3D as invitational then I think you need 4S as a control bid. But if you play 4C or 4H as Kickback then 4NT can be Exclusion.

[Lovera]

nullve, on 2019-February-16, 09:08, said:

My partner and I are trying to complete the auction on this deal:

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Is there any reason to believe 4♠ should be Exclusion in this position?

Conventionnaly it'd be Exclusion because the overcalling is not with a jump but had to be reached although almost the fourth level.

[pescetom]

Lovera, on 2019-February-17, 11:07, said:

Conventionnaly it'd be Exclusion because the overcalling is not with a jump but had to be reached although almost the fourth level.

If 4S would be Exclusion, how would he show (with a different hand) control of spades and no control of hearts?

[Lovera]

pescetom, on 2019-February-17, 11:13, said:

If 4S would be Exclusion, how would he show (with a different hand) control of spades and no control of hearts?

Infact l've said "it'd be" because seems the same situation as in #53 but theare we had heart as trump and 4♠ was upper game then when is showed this overcalling it is a previous forcing bid.