>>109381261
() is a capture group, in other regex applications you can use this elsewhere
(?:) is a non-capture group, it does the same thing but doesn't capture what matches
the difference doesn't have any effect on 4chan filters, it's for other uses.
> echo tummies | sed -r 's/tumm(y|ies)/captured: \1/'
captured: ies
> echo tummy | sed -r 's/tumm(y|ies)/captured: \1/'
captured: y