Hi, A tip some of you might find useful:
I wanted to separate sub-bibliographies by language, which is not one of the out-of-the-box available properties of the PRINT_BIBLIOGRAPHY keyword.[fn:1] Specifically, I wanted to filter out Norwegian items into one subbibliography and non-Norwegian ones into another in the same document.[fn:2] I found out how to do it with the `PRINT_BIBLIOGRAPHY: :filter <predicate>' property, which turns out to be used in the function citeproc-sb--match-p, where it is applied to a var-value list. I defined a predicate for Norwegian, bibitem-norwegian-p, that matches a regexp for various labels for Norwegian[fn:3] against the language value. #+begin_src elisp (defun bibitem-norwegian-p (vv) "Returns non-nil (0) if a bibliography item is in Norwegian. For use in an org-cite PRINT_BIBLIOGRAPHY filter." (let ((itemlang (alist-get 'language vv))) (and itemlang (string-match "n[obn][r-bo]?" itemlang)))) #+end_src Then I could successfully use it as follows: #+PRINT_BIBLIOGRAPHY: :filter bibitem-norwegian-p For the list of non-Norwegian items I just needed to define a complementary function: #+begin_src elisp (defun bibitem-not-norwegian-p (vv) (not (bibitem-norwegian-p vv))) #+begin_src elisp #+PRINT_BIBLIOGRAPHY: :filter bibitem-not-norwegian-p Adapt as needed for other languages and use cases. Refinements welcome. I'm especially wondering what would be an elegant way to generalize this for more languages without defining a predicate for each language (given that we cannot pass the language as an additional argument in the print_bibliography line). * Footnotes [fn:1] [[info:org#Bibliography options in the ``biblatex'' and ``csl'' export processors]] [fn:2] For this to work at all, of course, your CSL JSON or BibTeX has to contain language information on the items; it should, or English formatting such as title-casing might be applied inappropriately to non-English items by some styles. [fn:3] The regexp is complicated because Norwegian is complicated, my labeling is inconsistent and I want to match at least no, nb, nn, no-NO, nb-NO, nn-NO, nor, nob, nno, norsk and Norwegian ... Yours, Christian