In the last decade, an increasing number of online journals have begun publishing issues where the articles are all paginated independently. PLoS One is probably the best known, but several paleontological journals and journals by MDPI also have moved in that direction.
An example: https://www.mdpi.com/2075-4450/12/8/723/htm. Note that this is ''not'' a case of a journal where each article constitutes an issue. This journal's articles are formally arranged into issues.
Page numbers are completely useless for citing these articles (though I have seen it done). Usually there is an article number, but a format such as "12(8): 723" not only looks malformed, but is potentially misleading. I have not found any guideline in citation guides (I work mostly with Vancouver/CSE style) that cover this issue. Usually I plop an "a" in front of the article number ("12(8): a723") if there is not already a mean of telling it is such a number, but I'd rather have some sort of actual style guide advice...
Has any recent guide covered this corner case?
pages="723-1--723-16"
(making use of LaTeX's distinction between-
for a hyphen and--
for an en dash). I think this may have originally been inspired by the way APS journals with article numbers formatted the page numbers in footers c. 2000.