Proposal: “collection-title” as number variable; new CSL term for (Journal) “Series”

Proposal: Allow “collection-title” to be a number variable; introduce new
CSL term for “Series”, to allow for, e.g., “5” in a “collection-title”
variable to be ordinalized and combined with a term for “Series” in a
locale-specific manner to result in, e.g., “5th ser.”, or “5ᵉ sér.”, etc.

Rationale:

With certain long-lived journals, numbering of volumes starts over again at
some point in time. In the new journal series, volumes are then preceded by
“n.s.”, “new ser.”, or “new series”, “2nd ser.”, “3rd ser.”, or some
similar notation. For clarity, the old series may be designated by “o.s.”,
“old ser.”, “old series”, or “1st ser.” – see Chicago Manual of Style, 16th
ed., “14.195, New series for journal volumes”.

This has been discussed on the Zotero forum
https://forums.zotero.org/discussion/35399/correct-fields-for-entering-a-journal-series/,
where the consensus, for now, seems to be to use the “Series Title” box of
“Article Journal” items for this kind of information. “Article Journal” is
the only item type for which this seems to be relevant, and its “Series
Title” box is exported to the CSL variable “collection-title”. A number of
chicago styles have been updated to use “collection-title” for this purpose.

One detail, however, also proposed on the Zotero forum, is that it seems
desirable to be able to put a numeral, e.g., “5” in the series field, with
CSL generating the appropriate ordinal and abbreviation according to the
style, e.g., “5th ser.” – as it does for editions.

In the current CSL schema, this is not possible since “collection-title” is
not a number variable.

My proposal is to either allow “collection-title” to be a number variable,
or to use an existing unused number variable, e.g., “collection-number”,
“number”, or “edition” for this purpose. None of these are used in
“article-journal” items so far, and I do not foresee any future use case
for these variables in connection with this item type either.
Alternatively, introducing a new, dedicated CSL variable, e.g.
“journal-series”, might be an option, too.

In addition, I would like to propose the introduction of a new CSL term for
“Series”. The term’s name should be “journalseries”, “journal-series”, or
“jourser” since this would leave room for the introduction of a different
term for book series should the need arise. (Terms for journal series and
book series differ in some locales.)

Best,
Nick