What English to use?

We came to a small discussion on what kind of flavor of English language to use in Carpentry material,
https://github.com/hpc-carpentry/hpc-shell/pull/4#issuecomment-416965288
People say that en_US is the default for Carpentry material. Can anyone confirm or point me to related documentation? We would love to stay consistent with the carpentries as much as possible.

Thanks,
Peter

Start by reading the linked hpc-shell pull request discussion and the related Carpentries documentation referenced there, if available. The issue does not name a file or test or specify a concrete change; it would need an agreed English-language convention and a documented location for that guidance before implementation is defined.

Written by the indexing model from the issue text.