FILs 70th this weekend - he decided to have a black tie dinner at fairly posh hotel, invited his three sons, wives and 5 of the 6 grandchildren (our DS is too little to be up). GC range from 13 to 17.
One of the families got their children to dress v smartly. Other SIL let her 16 and 13 yr olds come in combats, v casual shirts with the sleeves rolled up, trainers.
I wasn't expecting them to be in black tie, but was it too much to ask that they wear a smart shirt, if not a tie too ?