Are questions about a reference system for academic documents off-topic?

Example, in reference to this question:

PubMed IDs (a.k.a. PMIDs) seem to have been assigned sequentially:

However, some some PubMed IDs missing. I.e. https://www.ncbi.nlm.nih.gov/pubmed/2260 returns Error occurred: The following PMID is not available: 2260. Why are some PubMed IDs missing?

  • @jakebeal Thanks for the edit, but what's the point of linking to the question? Too many people on Stack Exchange vote like sheep so it biases the answers. Or perhaps to people to case reopen votes? Nov 21, 2015 at 14:41
  • 1
    When there is a meta discussion triggered by a question, typically it is useful to link the question in order to provide context for the discussion.
    – jakebeal
    Nov 21, 2015 at 15:13
  • @jakebeal What context does it add? Are you referring to the comments on the question? Nov 21, 2015 at 15:14
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    First, it makes it clear that the meta question is not just discussing an isolated hypothetical, but an actual question on the site, which can affect how people think about it. There is also a lot of useful information at the question, not just the comments but also edit history, closure status, who voted to close, views, etc.
    – jakebeal
    Nov 21, 2015 at 15:19

1 Answer 1


In general, I think that questions regarding collections of scientific literature, such as PubMed, are on topic. Specific technical questions about details of their implementation, however, might not be. For example, I think most anyone would agree that a question like "Which operating system is used for the servers for arXiv?" would be off topic.

Your question about PubMed IDs strongly reminded me of this other closed question about the DOI structure of a particular journal. In both cases, it seems that any answer will basically boil down to "Because that's the way the database implementation happened to get set up" with no particular information or insight possible.

Do you have reason to believe that there may actually be something more than that behind PubMed's arbitrary system for assigning identifiers? If so, I at least would be happy to vote for reopening. At present, however, I see no reason to expect it to be particularly answerable or for the answer to be anything more than "Eh, databases, you know?"

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    Missing IDs may be due to technical issues or reference deletion. If the latter, I wonder what may cause a reference to be removed from PubMed. So I think the answer may be more than just cf auto-increment. (I find the other linked question interesting as well, and relevant to academia.) Nov 21, 2015 at 14:40

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