= bug description =

Today during a workshop for translation in Paris, one of the participant was trying to log using "Username" instead of "username", which did result in a error. After trying to reset the password several time, Patrick reminded us that the login must be in lowercase for fas and ipsilon (but not the wiki).

= bug analysis =

So the issue is that the user expectation is that the username would be ok, likely because he use uppercase for it on others systems. But the error message do not tell that.

= fix recommendation =

I would like to see if we can use javascript to warn that the username should only be lowercase, or directly convert it. I would favor the warning, as this can also warn for others constraints (like using utf8 by errors, typing space, etc)