Should we have a separate tag for questions about manuscripts?
I am not confident enough about what a manuscript (What are the boundaries between draft, manuscript, preprint, paper, and article?) to want it as a tag. As long as the tag wiki was clear enough, it might be helpful ...
In short, I don't think it would be helpful to introduce a new, very broad, tag that does not have a clearly defined scope distinct from existing tags.
There are three reasons I am not in favor of this proposal:
1) There is not much consistency in how people understand the word "manuscript," which makes it a bad choice for a tag name. We've even had a question asking about the distinction, as StrongBad brought up.
In my field, for example, I never hear people use the word "manuscript." People use "paper" when they are talking about an article in any stage of the publication process (both before and after publication).
Tag wiki excerpts are great, but underused, so if we think very few people will correctly understand a tag without referring to its excerpt, it's probably going to be a badly used tag.
Good tags should be easy to use and understand; "manuscript" vs "publication" is a distinction that means different things to different people, so it's not a good distinction to make in a tag.
2) We already have tags more specific than "manuscript" that I think would make the manuscript tag redundant. Questions about a manuscript would probably be about
- writing them, in which case they'd be covered by the writing tag
- circulating them, which would be covered by preprint
- submitting them for review or publication, which would be covered by paper-submission
When the more specific tags are used, they implicitly include "manuscript" - e.g. if a question has paper-submission, it is obviously about a manuscript.
You mentioned in a comment that it is wrong to use publications together with these tags. I don't think it is wrong. People use publications to distinguish between, e.g., questions on writing content that is intended for publication and questions on writing content that is intended for a thesis. It's a useful distinction.
3) Massive changes to the tag taxonomy need massive benefit to justify. This change would apply to a lot of questions, and I don't see massive benefit to this proposal.
It's not very disruptive to suggest and apply changes to tags on a small scale (i.e., less than a dozen questions). Changes on a large scale are more disruptive to existing users, and I prefer not to do them unless there's a very good reason. (And of course, large changes should preferably have a lot of support on meta before anyone undertakes them.)