The interwiki-xx class used in the language items in the ULS rewrite is missing for some languages. For instance, interwiki links to the Serbian Wikipedia used to have the class interwiki-sr, but don't have any interwiki-xx classes in the rewrite. The interlanguage-link and mw-list-item classes are also missing from all of these languages.
I noticed this because I am using this abomination in my personal vector.css, to color-code languages by language family and add flag icons in front of languages, so it looks like this:
It seems to affect the "usual suspects": Languages whose Wikipedia don't match the correct ISO code, or languages with multiple script. But still, I went through the interwiki links on https://no.wikipedia.org/wiki/Wikipedia and noted which ones aren't styled, and which lang attribute they use:
- bbc uses bbc-latn
- bh uses bho
- gom uses gom-deva
- iu uses ike-cans
- kk uses kk-cyrl
- ku uses ku-latn
- lad uses lad-latn
- map-bms still uses map-bms (but mw.language.bcp47( 'map-bms' ); returns jv-x-bms)
- nds-nl still uses nds-nl (but mw.language.bcp47( 'nds-nl' ); returns nds-NL)
- nrm still uses nrm (but mw.language.bcp47( 'nrm' ); returns nrf)
- roa-tara still uses roa-tara (but mw.language.bcp47( 'roa-tara' ); returns nap-x-tara)
- shi uses shi-latn
- sr uses sr-cyrl
- ug uses ug-arab
Much easier way to get this list in the browser console:
document.querySelectorAll( '.uls-rewrite__body__language-list li:not(.interlanguage-link)' );