W N E S
1♦ pass pass dbl
pas 2♦ pass ?
GIB convention card showed now following explanation for 3♦: 4+♣, 4+♥, 4+♠ BIDDABLE DIAMONDS !!! Since when at most singleton is biddable ?
I tried 3♦ nevertheless and was rewarded with pass from N (♠ Q75, ♥ KT92, ♦ AK52, ♣ 74)
Please do something with sequences like that

regards