[toomuchtodo]

If your account has met various criteria (seasoned, karma, no comment throttling, etc), you’ll have a vouch option (unless you’ve done something to be in the penalty box permanently; sufficient karma, no comment throttling, no vouch).

[greyface-]

Note, though, that the vouch link only appears when the submission has been flagkilled (i.e. [flagged][dead] and not just [flagged]).