Your husband can ABSOLUTELY wear shorts at brunch. I vetoed this for my husband (2 weeks ago) as I thought it wasn't allowed and when we got in line to be seated 2 couples ahead of us,were wearing shorts. So, I says to the maitre'd (to prove my point to DH that those people were breaking the rules), "you don't allow shorts at brunch do you?" And he says "Oh yes ma'm, we relax the rules at brunch and we do allow Khaki button down shorts with a casual shirt". So, I did get a little ribbing from DH on that one! Of course, you don't want to go in cutoffs or Ronjon bermudas but he did say that khaki button down were appropriate and we saw lots of men wearing them with nice polos. I did not see any woman wearing shorts, but lots of capri's.
Jenn