Recently some changes were made to the way comment flags are stored in the DB, such that it's now feasible to display them alongside flags on regular posts in a user's flagging history.
This was requested a year and a half ago, and has a reasonable amount of support (I even seem to have upvoted it myself). The (perhaps unanticipated) problem with it, however, is that, except for declined comment flags, these entries are next to useless. The response to a helpful comment flag is uniformly deletion of that comment, so there's nothing that can be reviewed. The link in the history entry just goes to the post to which the comment was attached, and unless you remember exactly what comments you've flagged, there's no good way to tell what happened. Older flags especially are just clutter in the list.
Still, I'm sure there are people who are interested in seeing these flags, so I'd like to request that helpful comment flags be optionally left out of the list, à la the checkbox we have in the reputation history list to show or hide deleted posts. Leaving declined comment flags permanently on display makes sense to me, since there's something to see: "Okay, the mods don't think 'Try JQuery' is 'not constructive'; I guess I'll stop flagging those", but they could certainly be hidden too.