discourse | Locale

user username blank
en	must be present
pl
user username characters
en	must only include numbers and letters
pl
user username long
en	must be shorter than %{max} characters
pl
user username must_begin_with_alphanumeric
en	must begin with a letter or number
pl
user username short
en	must be longer than %{min} characters
pl
user username unique
en	must be unique
pl

sanderdatema discourse