Often you need a notation for a finite sequence with one element is removed; i.e. $$(x_1,\dots,x_{i-1},x_{i+1}\dots, x_n).$$ I know one notation $$(x_1,\dots,\hat x_i,\dots, x_n)$$ and I hate it. It is too long and it has no sense; i.e., unless you know the meaning you will never guess what is it.

Question: Did you see any other?