On Esperanto SE:
- tag names in Esperanto (optionally with synonyms in English) are sub-optimal for Esperanto SE users who don't (yet) know Esperanto well
- tag names in English (optionally with synonyms in Esperanto) are sub-optimal for Esperanto SE users who don't know English well
- multi-lingual tag names could solve this dilemma
Esperanto Language Stack Exchange allows questions (and answers) in both English and Esperanto. And indeed, some users know only one of these well enough to write in it, and that should be OK. (Especially considering that one of the purposes of Esperanto is to serve as an auxiliary language that's easier to learn than the current de-facto lingua franca.)
This also means that tags must work for people who know English well, but no or only a little Esperanto, but also for people who know Esperanto well, but no or only a little English. For adding tags, that's kinda solvable by having someone who knows both languages add or suggest tag synonyms. But tags should also be recognizable by all users of a site and ideally without always having to refer to the "Usage guidance (excerpt)" or the full description in the tag's wiki.
Suggested Feature Change
Thus it'd be nice to have tags that are actually displayed bilingually, as I've suggested at my answer to "Language of tags" on Esperanto Language Meta. To rephrase it: It'd be nice to, e.g., have a tag "muziko — music" on Esperanto Language Stack Exchange, and to have muziko and music as synonyms for it.
Whether this would better be accomplished by allowing spaces and "—" in tag names, or whether tags would better be changed to have a separate name in each language defined for a site that are then displayed together, I'm unsure. I'm leaning towards the latter, because that'd also save us from configuring the monolingual→bilingual tag synonyms manually.
I'm posting this on Meta Stack Exchange, because this would probably need a change in the common software of all Stack Exchange sites and because I think this could benefit other Language-topic Stack Exchange sites, too. (Some of them, like French Language Stack Exchange currently use mostly non-English tags, while others probably use mostly English ones or a mix.)