I am trying to develop a Biblatex style for English (academic) legal citations. For the moment I am not trying to deal with the citation of cases (which is going to be very tough), but just with the citation of basic literature -- i.e., things like books, articles and so forth.
The most common citation style here (see, e.g. OSCOLA) is similar to that used in humanities fields such as history, so that the "historian" style forms a good starting point.
Legal journals have two distinct and different ways of dealing with years and volumes. Some/most journals have consecutively numbered volumes, where the year provides "extra" and in a sense optional information, i.e. the reader could find the journal from the volume number alone. These are cited as
Some Author, "An Article" (2010) 126 LQR 237
But other journals don't have volumes in this sense. They use the year of publication as the volume number. In that case the year of publication is put in square brackets rather than parentheses:
Some Other Author, "Another Article"  PL 237
My question is: what is the best way to deal with this formatting requirement? Is it one that crops up in other areas? Is there a conventional approach? Among the possibilities:
If the year is the volume, then enter the volume as "[YYYY]" in the
.bibfile, and leave the year blank. That seems simple to implement; but I don't like that it produces a
.bibfile that is in some sense "counterintuitive", because one doesn't think of "2010" as a volume number, but as a year!
If the year is the volume, then enter simply the year in the
.bibfile, and leave the volume blank. In the style file, detect if there is a year but no volume, and if so use the square-bracketed form. I marginally prefer that to the previous option, because at least the "semantic form" of the
.bibfile resembles the way I would "naturally" think about this situation; but I'm concerned that I might get bitten by odd cases where there is (legitimately) a year but no volume number, but this particular form of citation is inappropriate.
Given that the number of journals that use this particular referencing system is not huge (though it includes some very commonly referenced journals), write some sort of test in the biblatex style files to check for those particular journals. That sounds like a recipe for error, and missing cases. It also fails because some journals have changed their referencing system at some point, so one would also have to check the date. I'm inclined to reject it.
Use a keyword to signal where a journal uses this system, and write macros that typeset accordingly.
Do similar issues occur in other areas of work? Is there a conventional way of dealing with them?