[helene_t]

Raising clubs with a 4-card major makes a lot of sense to me. If you start with spades, you need a way to show clubs forcingly in the next round. Playing Pavlicek's method (described here by Hannie as "New Suit Invitational") helps, but if partner raises spades on what might be a 3-card, it can become muddy.

Dutch experts Brulleman/Wijma play inverted minors raise with 4-card support and a 4-card in a major (or even both majors). But they need a GF hand to raise. I think this is related to the auction:
1m-2m
2NT-?
If responder has an invitational hand with a 4-card major, you may be playing 2NT when you have a fit in a major suit.

I suppose you could agree that an inverted minors denies a 4-card major unless you have GF values.

[kenrexford]

FYI -- an approach that works well for this hand and that I prefer:

1♣-P-2♣ is either GF and artificial (no 5-card major), or club fit and invitational+.

Opener rebids one-under a four-card major if he has one, or 2♠ without a major, 2NT with balanced (and appropriate for range), 3♣ with a club-diamond reverse hand, 3♦/♥/♠ solo splinter, 3NT balanced higher range (usually go through 2♠).

On this one, if Opener bids 2♥ (spades), great! Bid 2♠ to agree on the 4-4 spade fit and start cuebidding.

If partner bids 2♦ (hearts), you can bid 2♠ (in case he is 44 in the majors). If he also has a spade fit, he will probably agree spades at 3♠ (or some picture jump or splinter) and you are again cuebidding.

If partner bids 2♠ or 2NT, 3♣ by you would be invitational only. So, you can bid 3♥, agreeing clubs as the focus, GF, isolating a diamond hole, and either NT probe or slam probe.

If partner bids 3♣+, you are off to a grand most likely.