Trump Request

There are 3 situations where Trump Requests can arise:

(i) 2C sequences: E.g. 2C - 2H- 2NT is a trump inquiry in Hearts; 2C - 2H - 2S is a trump inquiry in Spades etc.
(ii) 1NT - 3X (4 steps for X=Major; 2 steps for X=minor - these are the 3rd and 4th steps as 1st and 2nd are impossible)
(iii) 1X - JY

In case (i) A 2nd trump request can be made in a second suit if and only if the first suit got a negative reply (step 1)
In case (iii) If a negative is given to Y then the responder automatically rebids as if a trump request has been made in 'X'.

Thus: 1X - JY - next bid - then 4 step response for 'X'.

If my 'code' is unclear then here's an example:

1H - 2S - 2NT(1st step, negative, opener shows Jx or less in Spades) - 3D(2nd step, limited support, responder shows Qx --- Jxx in Hearts)

Following a 2 negative response of 2: 2, 2, 3 or 3 are trump requests or of 2NT: 3any are trump requests
Following a 2 positive response of 2 or 2, 2NT is a trump request in the suit of the positive response - saving bidding space - otherwise bid the candidate trump suit itself
In the special & happy case of a 3NT response to 2, Opener now 'names' his trump suit or bids 4NT (NT hand) and in both cases responder specifies the number of kings held. It will be a question of either a small slam or a grand slam!

There are usually 4 step responses to a Trump Request
These 4 steps will be the next 4 possible bids and NT bids by responder count as steps too

Step1 xx or less excluding Hx where H is A¦K¦Q

Step2 xxx or less excluding Hxx where H is A¦K¦Q

Step3 xxxx or less excluding Hxxx where H is A¦K¦Q

Step4 xxxx headed by A¦K¦Q or any xxxxx

If intervention occurs prior to giving your response

The available 4 steps become:

PASS
*¦**
Next bid
Next+1 bid

There is just one exception to 4 steps when the request is made with a jump in a minor in response to a 1NT opening when there are just 2 steps - missing step 1 & 2. (As 1NT promises Qxx or xxxx in any minor. See 1NT)

Subsequent bidding

Following a positive response (steps 2, 3 &4); control requests can follow OR 4NT for Kings & trumps are deemed agreed
Following a negative response (step 1) one more trump request can be made - if opening was 2

, other options are rebid your suit at any level or any NT bid to play - except 4NT which is for kings & 5 of your suit which inquires for top honours in the trump suit
Following a negative response (step 1) following 1suit - Jnew suit then the responder rebids as if a trump request is made in opener's suit - and if a positive response control requests follow else return to a previously announced suit or NT contract

Note: In very strong two suited hands each 5+, then the choice of which to make a trump request in is important.
There are two guidelines:
(a) Usually choose the one that uses up least bidding space
(b) Avoid making a trump request in a solid suit
For example with

AQTxx

AKQxxx

x Technically a 3 1/2 LTC. Choose 2

- 2

- 2NT...