rbforster, on 2010-December-21, 17:26, said:
Under a reasonable reading of GCC, you can play 1♦ showing 4+ spades and 10+ points, and 1♥ as 4+ natural. Of course this doesn't give you a chance to use 1♠ for diamonds or other nice features, but you could try this:
1♦ "0+" 4♠ unbalanced canape or 4(441), 4S/5+m or 4S/5+H
1♥ 4+♥ unbalanced. Hearts and a minor, either longer, 1444, or 6+ single suited
1♠ 5+ standard
1N 12-14 balanced, includes 5H(332)
2♣ 5+ constructive - 6+ or 5m/4+om (no side major)
2♦ 5+ constructive - 6+ or 5m/4+om (no side major)
If 1♥ seems too overloaded here (I think it's manageable with KI and 1H-1S-1N showing 5H/4+m), you can remove the 6+ heart 1-suiters to 2♥.
1♦ "0+" 4♠ unbalanced canape or 4(441), 4S/5+m or 4S/5+H
1♥ 4+♥ unbalanced. Hearts and a minor, either longer, 1444, or 6+ single suited
1♠ 5+ standard
1N 12-14 balanced, includes 5H(332)
2♣ 5+ constructive - 6+ or 5m/4+om (no side major)
2♦ 5+ constructive - 6+ or 5m/4+om (no side major)
If 1♥ seems too overloaded here (I think it's manageable with KI and 1H-1S-1N showing 5H/4+m), you can remove the 6+ heart 1-suiters to 2♥.
So, I came up against this opening structure at the regional in London, Ontario not that long ago with the only difference being that they opened 1!D with 5!S-6!H. I was unsure as to the legality of this and ran it past Mike Roberts and Gary Zeiger (both national-level TD's) at the next nationals and they were both explicit that this structure is GCC legal. I asked "but is the 1!D really 'catch-all?'" and they both replied "yes" that catch-all can mean whatever the user wants.