Whats's the difference between the csl number-variables "issue" and "number"?
https://docs.citationstyles.org/en/v1.0.2/specification.html#number-variables
I don't see any difference between an issue of a journal and an issue of a report.
I don't see any difference between an issue of a journal and an issue of a report.
Number is typically a unique identifier within the context of a publication -- for example, there is only one GAO report GAO-24-107306
Number can also be used for journal articles published exclusively online, which only have a (unique) article number. Some styles (notably APA) treat article numbers different from page ranges, thus requiring separate treatment and, in some cases, co-existence with issue.