Is there some other way to find out which words in the title and which tags are blacklisted other then experimenting and browsing through posts tagged blacklist and tag-blacklist?

Would it be useful to have such list publicly in a post on meta? (If available, together with links to discussions on meta which lead to blacklisting particular word/string/tag.)

Or are there some reasons why it is better if this information is not publicly available?

@MartinSleziak A long time ago in a chatroom not-so-far away I listed our then-current list of blacklisted tags:

@MartinSleziak This could be useful, although for certain of the tags, I'm not sure where the discussion is.

I should have remembered this.

Even without clicking on the link, I can guess who was the user who asked about that list.

@MartinSleziak Some of the blacklisted input is more sensitive (some stuff that helps prevent certain types of spam). Blacklisted items that we've requested are probably safe to state publicly.

@ArthurFischer That seems reasonable. (I guess it is still visible to mods.)

@MartinSleziak Yeah, we've got a list to the entire list. I'm trying to copy parts of it over here now. Gimme a few minutes.

Intrinsic Tag ^equations?$
Intrinsic Tag ^gm\.general-mathematics$
Intrinsic Tag ^math(ematics)?$
Tag ^algebra$
Tag ^completeness$
Tag ^graphs?$
Tag ^homework$
Tag ^proof(-strategy)?$
Tag ^untagged$
Post Title \$\$
Post Title ^.{0,30}(^|\W)(anyone|difficult|doubt|easy|hard|help|interesting|please|problem|query|question|someone|stuck|very)(\W|$).{0,30}$
Post Title ^(?-i:\P{Ll}+){15,}$
Post Body ^(?-i:\P{Ll}+){30,}$

These are the regexs. The last two prevent titles/bodies without lower case letters (though it gives a "STOP SHOUTING" warning).

I will bookmark this for future reference.

Is it sufficient to leave it here, or should we make a post on meta, too?

@MartinSleziak Meta post doesn't hurt, I guess. Then it is expandable. I'd perhaps leave out the last two, since they are site wide, I believe.

BTW I have certainly seen many posts with question, problem, difficult etc. Are thay really blacklisted or does that line only give a warning?

@MartinSleziak Might be a warning, but it's only for short titles.

Yeah, seems to be only a warning.

I see, the number 30 means that title has at most 30 chars, right?

@ArthurFischer Will we make a post on meta only for blacklisted tags or both blacklisted tags and blacklisted words?

@MartinSleziak I believe that's at most 30 chars before and 30 chars after. My regex skills are rather poor.

Will you post a question on meta or should I do it? The answer should definitely come from a mod. But I am certainly willing to help with searching for older post on meta where blacklisting was discussed.

@MartinSleziak I'm going to be busy for a little while pretty quick. If you want to start something, go ahead. Most of the requests are out there, with acknowledgement that they've been enacted. I don't think the answer coming from a mod is necessary. The answer probably should be CW, however.

@MartinSleziak Yeah, I'm mostly uncertain where there ^equations?$ blacklist came from. The rest I have an idea about.

@ArthurFischer Ok, unless something else pops up, I will make post on meta and the CW answer.

@MartinSleziak Sounds good!

@ArthurFischer Accidentally, I have mentioned this a while ago in Tagging chatroom.

If you need to, link to my message above for "proof" that they come from a reliable source. ;-)

@MartinSleziak Ahhh..... (It's old, just like I thought.)

@ArthurFischer I have made post on meta and a CW-answer for blacklisted tags.

Feel free to edit it if you want to add something. (For example, I did not list the exact regular expressions.)

And I did not mention the blacklisted phrases in the titles. Basically the only thing I am aware of are the double dollars.

@ArthurFischer Sorry for pinging you once again. You have mentioned exercises-and-solutions and according to this answer by Tim Post it was blacklisted. By I do not see it in the list of regular expressions you copied here.

I have added it to the list, I guess you (or some other moderator) can confirm whether it is indeed blacklisted and correct the information given in the answer (if needed).

@MartinSleziak I see no evidence of it in my list, and I seem to be able to add it to questions.

(Not that I would add it.)

Strange. Since Tim Post's answer says: "The tag has been burninated and blacklisted."

In any case, that is up to mods, what to do next. (Whether blacklisting this tag, or more generally tag containing the phrase exercise, should be requested again.)

And I should also say, thanks a lot for your help. (Both here in chat and also for editing the answer.)

@MartinSleziak Yeah, I'll try to contact a CM and see what happened. It used to be black-listed, but I'm uncertain why it would be removed.

At the moment, the question has 9 views and the answer has already 7 revisions :-) Thanks to everybody for their improvements of the post! (Although in this case everybody mainly so far means the Fischers.)

@MartinSleziak Yes, there's a warning but users posting a question generally want to get it posted now, so various warnings and advice tend to be brushed aside. My bot comments on questions with such titles, using a similar regex; in many instances, this leads to an edit. It seems that users are more receptive to suggestions for change after they posted, since they got their primary goal fulfilled.