Task #94347
closedResolve inconsistency in naming of Site Configuration language attributes and TypoScript naming for accessing language attributes
100%
Description
Since 9LTS (10LTS and master, too) Site Configuration has a language option for defining the flag and the twoLetterIsoCode.
In Site Configuration it is called `flag`: https://docs.typo3.org/m/typo3/reference-coreapi/master/en-us/ApiOverview/SiteHandling/AddLanguages.html#flag
In TypoScript one can access this via `flagIdentifier`: https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/DataTypes/Properties/GetText.html#sitelanguage
In Site Configuration it is called `iso-639-1`: https://docs.typo3.org/m/typo3/reference-coreapi/master/en-us/ApiOverview/SiteHandling/AddLanguages.html#iso-639-1
In TypoScript one can access this via `twoLetterIsoCode `: https://docs.typo3.org/m/typo3/reference-typoscript/master/en-us/DataTypes/Properties/GetText.html#sitelanguage
As all other attributes seem to be 1:1 the same identifier, this could perhaps be harmonised. Of course this would need a converter/fallback/migration and I can't decide which might make more sense to adapt.