While creating a new repository, a language can be selected from the pre-defined list of languages. Can this be customized to add something which is used internally by an organization ?.
If that is not possible, is there a way to associate custom metadata to a repository and can REST api return the details of a repository. The idea is to use the custom language and use Bitbucket REST api's to list the repositories that have this custom language set.
Even though this is a very old question, it appear as the first hit on Google, and obviously is still popular.
Atlassian has still not improved the list of languages, although it still leaves a lot of things to be wished for.
I have therefore created this feature request: BCLOUD-21015
At the moment, it's not possible to add extra languages to the pre-defined list of languages in Bitbucket Cloud. However, you can submit a Feature request for the consideration of our team. You can use this one as an example: https://bitbucket.org/site/master/issues/3676/request-to-add-language-to-programming.
For your second question, my advice would be to visit the Developer Community and see if one of our members there can share some knowledge about that with you.
Hope that helps,