root/admin/attributes/create.tt (for admins to add languages, entity types, and similar attributes) and root/admin/attributes/edit.tt (to edit them). They're wrappers for the same form, which also needs to be converted.

It might make sense to split the form into 3 or 4 files - right now, there's basically language, script and generic forms, but they are all in the same file with IF/ELSIF/ELSE.