INVALID_USERNAME: str = "error: username invalid"
INVALID_PASSWORD: str = "error: password invalid"
INVALID_USERNAME_PASSWORD: str = "error: username or password invalid"
USERNAME_ALREADY_USED: str = "error: username already used"

USER_ADDED: str = "ok: user added"
USER_DELETED: str = "ok: account has been deleted"
USER_VALID: str = "ok: account valid"
PASSWORD_UPDATED: str = "ok: password has been updated"