[Gilithin]

 mw64ahw, on 2022-September-19, 04:37, said:

I play something totally different now, but originally learnt, as here, to consider fast vs slow arrival so opening ♣ and rebidding 2♦ keeps the bidding lower so shows the stronger hand.

I suspect there was some misunderstanding there. In standard natural bidding, it has always been the case that a reverse shows not only extra values but also specific shape features. It is not unusual for a reverse to be faked with a (4441) hand but I know of no completely natural system that routinely does this with 5-5 in the minors.

That said, there is a method that some pairs use where a 2♦ rebid after a 1♣ opening is artificial and does not promise diamonds. In that scheme, typically a strong club one-suiter (BWDH) gets bundled in and is identified by Opener bidding 3♣ after Responder relays. There is also space for one further hand type. Most pairs using this seem to choose a big balanced hand here, thus freeing up their 2NT rebid for a raise of Responder's major, but you could use it to show a reverse strength 5-5 hand if you preferred, thus saving you 1 step (2NT vs 3♣) over standard bidding. So yes, it can be done but the gains versus losses are questionable and as a convention it certainly has no place in the N/B forum.