Redmine

Hi all,
I have renamed a bunch of project manually by changing the database associated to my Redmine instance. Everything is working perfectly well and I am happy with the change so far. However, I am worried about my usage of _ instead of - as part of the identifier. As I know that _ are not allowed when you create identifier in the UI, I was wondering what is the reason for excluding this character from the authorized set of characters.

Regards,
Olivier