It often isn't so much the actual bibliography line item format, which are usually handled quite well be systems like bibtex or biblatex+biber, but overall cita

It often isn't so much the actual bibliography line item format, which are usually handled quite well be systems like bibtex or biblatex+biber, but overall citation formatting complexities. Sometimes journals want specific formats that become a challenge to implement. For example, on a recent submission, we needed our main text to have a numbered bibliography at the end, then needed our methods to have numbered bibliography at the end, but with numbers starting after the last number in the main text, and no repeats, but with references in the methods to items already in the main text bibliography referring to those numbers. This was surprisingly difficult to implement reliably in LaTeX and Biblatex. An additional annoyance is that to save space, journals often want formats that are compact but inefficient to use, for example, formats that are heavily abbreviated and don't include titles. These, however, are annoying to use, and annoying reviewers is generally unwise. So in our case, we actually intentionally submit PDFs for review that use the 'wrong' bibliography item format, of a similar form to the journal's but less abbreviated and including titles and hyperlink backreferences to citations in the text. Then for final submission we have to replace this with the journal's preferred format.