bibliography entry filtering strategy

[Omikhleia]

With #2082 we'll have a \printbibliography command, outputting a sorted bibliography (with, currently as proposed, an option cited=boolean)...

Let's think further.

I don't remember the name of the corresponding (La/Bib)TeX command and its details, and I like to have my mind clear from influences... but what I remember from my younger self: for sure, there's some feature for filtering part of the bibliography.

Example use case:

• I've citations to books, articles from journals, in-book chapters, book reviews, &c.
• I'd possibly want to split the bibliography according to some criteria (cited books, cited articles, &c), with my own headings and introduction text before these bibliography subsets.

--> This issue is for tracking the idea, compare it with other solutions and propose something interesting.

(Bib/La/Tex would for instance likely allows to filter on its "document types" (the @type in .bib entries), but what would this mean in a grander scheme if our target is CSL types? And how one can distinguish primary sources to secondary sources, etc. or what does it imply for "reviews" which are at the same time "regular" articles in some publication?) = Some analysis of existing solutions might be a prerequisite if we don't just want to "mirror" what Bib/La/TeX does, without questioning it.

[Omikhleia]

Without forgetting thematic filtering (based on "keywords"?) e.g. all cited references on "Geography", then "Mythology", &c.