There was a question I answered put on hold as having "too many possible answers, or good answers would be too long for this format". I understand the reasoning behind that sort of hold in general, however I don't understand why it was applied in this circumstance. It's quite evident from some of the parts of the question that the questioner didn't understand the system he was asking about, but that can't be uncommon here. I understood what he was asking, and it seems the person asking the question thought my answer was clear. So, in this case, is there any recourse? Can the hold be removed, and if so, how?
Questions are placed "on hold" when the community (or a moderator) have decided that the question is not a good fit for the site. If a question remains on hold long enough, it will be marked as "closed."
A hold (or closure) can be removed when the community (or a moderator) decide that the question suits the site's criteria. Typically, this is after the question's original poster has edited the question to bring it back into like with what we want on this site.
So, the easiest way to un-hold or reopen a question would be to simply edit the question to fit the site criteria. The community will take it from there.
Note that it's also possible to "appeal" a hold in Chat or in Meta, which will either result in the question being re-opened or you getting a better explanation about why it was closed in the first place.
If you want more information about the closing process, please look at What does it mean if a question is "closed" or "on hold"? in our Help Center.