I found an older convention card and located in this a few scribbled notes. I'm not sure if I ever posted the idea, but I kind of like it. The idea concerned a better way to find major fits after Opener starts a strong Two Clubs and then rebids a minor.
First, after a 3C rebid, 3M promises 5+, with 3H possibly showing 5H/4S. So far, nothing exciting.
Second, after 3C, Responder's 3D is "modified Stayman." Opener bids 3NT with hearts or 3S with spades. With no 4-card major, Opener rebids 3H. This allows Responder to then rebid 3S with 5S/4H.
So, after 3C, Responder has these options:
With just five spades, bid 3S.
With five spades and four hearts, bid 3D modified Stayman and then, if necessary, bid 3S after the 3H-no-major rebid.
With just five hearts, bid 3H.
With 5H/4S, bid 3H and see if opener bids 3S.
With one or both 4-card majors, bid 3D.
The simplicity of this is the key. Everything is natural, except that Opener rebids 3NT to show four hearts and rebids 3H to deny a four-card major after Responder's artificial 3D rebid.
So, next to the 3D rebid. Opener solves the problems himself, by describing his major holdings, a reversal of roles!
2C-P-2D-P-3H = diamonds with four hearts, and might be 3451 (Responder needs five spades to introduce them).
2C-P-2D-P-3S = diamonds with four spades, with fewer than three hearts.
This eliminates some holdings from the 3D rebid. Not all that the one common method uses are included (which leaves a problem finding the 5-3 heart fit if Opener is 4351 or 4360).
Opener's 3D call, with these methods, becomes a "natural but Puppet" call. Responder can bid 3S with five spades (as usual) or 3NT with five hearts! (With five hearts and extras, a higher call would work.) With no five-card majors, Responder rebids 3H. This allows Opener to rebid 3S with 4351.
This method allows Opener to distinguish/handle the "other major" sufficiently for Responder.