I have an accepted manuscript published in an Elsevier engineering journal. The status of the article on its sciencedirect page is "In press, corrected proof". For now the article can be cited using its DOI and year of publication (2017). However, the journal is now working on two volumes: the December volume of 2017 and the January volume of 2018. I have noticed that some articles accepted after mine have been assigned to the January 2018 volume, while my article and some other articles accepted within the same week (1-7 July) are still in the corrected proof status. So I have two question: 1- Can the article get assigned to the January 2018 volume considering that it is now cited as an 2017 article? 2- Is their any priority criterion for publishing? Topic? First submission date? ... etc?
Re. 1 - Yes. I have a paper that was published "epub ahead of print" in one year, and later published normally the next year. Both versions have different year numbers when cited.
Re. 2 - I would expect they do it in chronological order normally, but sometimes journals publish "special issues" on a specific topic that result in postponed or quicker printed versions. Also comments/replies to specific papers often get published in the same issue, suggesting that those ended up in print version quicker.
I don't think there is a uniform consensus on it - academic publishing has a long and rooted traditions on what is "right", but they do not explain what to do in the Internet era, when almost every result is first available as a preprint online.
However, I believe, we normally don't put a year on a paper unless it is published. I've seen something like:
A. Author. The greatest paper. In preparation.
A. Author. The greatest paper. Submitted to J. Cool Research. Available at ArXiV:1709.XXXX.
A. Author. A nice paper. Under review in J. Cool Research. Available at ArXiV:1709.XXXXv2.
A. Author. Another paper on cool topic. Accepted in J. Cool Research. Available at ArXiV:1709.XXXXv3.
A. Author. Another paper on cool topic. J. Cool Research (in press). doi:1701.10/xxxxx.xxxxx. Available at ArXiV:1709.XXXXv3.
A. Author. Another paper on cool topic. J. Cool Research vol X, pp. yy-zz (2018). doi:1701.10/xxxxx.xxxxx.