After selecting British English during core installation, the installation is halted and an error is reported:
The English, British translation is not available
The English, British translation file is not available at the translation server. Choose a different language or select English and translate your website later.
This error is caused by a missing translation at the localize.drupal.org server. For British English (and some other languages) no translations are available at all: http://localize.drupal.org/translate/downloads. Missing translation are usually the result of translation teams which have not (yet) started. The druapl installation uses the languages returned by
standard_language_list(). This list roughly matches the languages available at l.d.o, but does not take into account the languages for which no translations are available at l.d.o. Therefore not all languages presented at installation are actually available for installation. This is not a good user experience.
One of these solutions:
1. #568986: Dynamically update standard language list from localization server
2. Add an extra field to standard_language_list() to indicate the availability of translations at l.d.o
3. Create a new function that return a list of not translated languages.
Not translated languages can be removed from the language list at installation (solution 2 and 3). But can also be used to ignore during automatic language import.
to be determined
User interface changes
The list of languages presented during installation, will only contain the languages for which at least a drupal core translation is available.
to be determined