Vanilla 1.1.9 is a product of Lussumo. More Information: Documentation, Community Support.
I've been wishing for a while that we could reduce the level of "meta" noise in the comments on the main site. (By "meta" here I mean anything whose meaning or intent is contingent on the particular nature of mathoverflow itself, rather than mathematics per se.)
I see the ideal as only comments explaining votes to close, and in the case that there is any controversy, a neutrally worded link to a meta thread. Now, of course it would be crazy to legislate this, and hence this proposal is for a new piece of MO etiquette. In the event that comment threads get out of hand, e.g. the recent comment thread on the question about third derivatives, we could at least point the "culprits" to evidence of established consensus that this behavior was "impolite".
Specifically, I propose that we consider it "impolite" to leave multiple "meta" comments on a single post. This imposes no burden when a question is uncontroversially closed, and it doesn't interfere with the ideal that votes to close (and downvotes!) are accompanied by explanations (and ideally suggestions for alternative venues or improvements), and it still allows anyone with an opinion to "fire and forget".
If one anticipates wanting to make multiple meta comments, then it behooves one to create a meta thread right away, and include that in the first comment. (In utopia, the poster would also wait to stand on their soap box until they're over at meta, leaving only a neutrally worded link; people shouldn't dishonestly "get the last word in" by diverting responses to meta.) It would be every so slightly impolite to do this in ones second comment instead.
I'd also like to remind everyone to vote up comments with links to meta, to ensure people see these, and help divert meta traffic here. I'm also happy for people to word their meta links more strongly, e.g. "I have created a a thread in meta <link> to discuss this question. All further meta discussion should take place there."
(This suggestion is inspired by the successful operation of a similar rule on the Berkeley climbing club mailing list. We love to digress onto subjects such as whether cat urine affects the strength of nylon webbing, but it's really intended as a mailing list for organizing trips. We have a rule of two posts per person per thread, before you're expected to take it off list, but it's only "enforced" via curmudgeonly reminders.)
Hah! First you impose these draconian conditions on me, and now you've imposed them on everyone else! The slopes on MO are very slippery indeed!
(Also, joking! If you don't get it, don't worry about it.)
And to clarify, just in case, I'm not proposing that this affects "mathematical" comments at all, and further we should interpret the grey area very generously.
cat urine related comments count towards the limit?
1 to 5 of 5