I wasn't the mod who declined the flag; I suspect I'm representing their reasoning, but I haven't spoken with them about it. That particular comment appeared to have been understood by everyone involved in the post, judging by subsequent replies. (Heck, I can only guess at the language, but it looks like something about doing physics at a particular institution in Zagreb; that guess was borne out by other comments in the thread.)
Comments are meant to be transient, and that discussion was a dozen years old, so now all those comments are gone.
To some of you other points:
Why are the moderators allowing otherwise?
As a rule, we don't. But we don't make a habit of combing ancient posts for incomprehensible snippets, either. We don't tolerate questions or answers that are completely in non-English languages, and we probably would remove a comment thread that was mostly in a non-English language. A single sentence in a discussion that stays in English is a different creature.
the flag was a) declined, b) done so without any explanation
We can leave explanations when we approve or decline flags on questions or answers. But we can't attach explanations to flags on comments. Old comments just aren't a big deal.
I'm also going to respond to some other things that arose in comments. I want to make it clear that not all of these issues were raised by the same user.
My issue with this situation is, it is way too easy for you to ruin new user's flag weight. The comments are gone, and the flag is still marked as rejected, tainting the record.
This also really isn't a big deal. If you have too many flags declined, you might not be able to raise new flags for a few days. I thought I had remembered that there was a list of users who had hit this limit, and that it was empty. But instead it appears that there is no record of which users are restricted from raising flags. Not being able to raise flags doesn't affect other things you might like to do on the site.
I believe that it was the moderator's misjudgment
Perhaps. I'm not too worried either way about a single comment flag.
And acting upon the flags is the expected behavior
You are a frequent flagger, and somewhere north of 95% of your flags have been marked as helpful. This "expected behavior" is the norm for you. This is what healthy flagging looks like.
in less than a month you have flagged 150 things? Do remember that the mods who responded to them are unpaid volunteers.
Our dashboard says that we've handled 800 flags in the last month. Most of those got handled by the review queues, without intervention by the diamond moderators.
Three dislikes so far, keep them coming
Votes on Stack Exchange aren't "like/dislike"; they are "useful/not useful." I frequently like things that are not useful, and vice-versa.
Spoken (or rather written) like someone who understands only English
calm down … Next time, think before posting a condescending comment like that
Your comment is extremely patronizing and judgmental.
To repeat: not all of the quotes in this section are from the same user. But this fighty stuff isn't okay. Be polite to each other, or look at some other website for a while.
I think this edited version of the answer addresses the issues raised in the comments, so I've removed them.
