For example, in simple.wikipedia.org, the content language is 'en', but when it's used, it needs to be defined as source or target, it needs to be 'simple'. The current way is to use wgServerName, as was done in https://gerrit.wikimedia.org/r/#/c/226552/ , but it could probably be cleaner. This could be a variable set by core, something in CX's SiteMapper, or some other solution.
|Open||None||T102107 Enable Content Translation in Catalan Wikipedia for all logged-in users|
|Open||None||T116533 ContentTranslation issues that affect people who aren't editors or translators (tracking)|
|Open||None||T126916 ContentTranslation gray interlanguage links issues (tracking)|
|Open||None||T105577 use geolocation to show the gray interlanguage link in ContentTranslation|
|Open||None||T105578 Incorrect language code handling in ContentTranslation (tracking)|
|Open||None||T106723 create a robust way in which ContentTranslation could know the language code in edge cases|