Comic NT is a 1NT overcall showing a weak jump overcall in an unknown (but unbid) suit.
So, 1 - 1NT
shows a weak jump overcall to 3
or 3
or 3
.
Partner bids 2
if 3rd hand passes and you name your suit.
It is useful if you save your jump overcalls for something else (Roman, Ghestem, Intermediate, etc.)