constant USER_LOGIN_USERNAME_ONLY

Users can login with username only.

6 uses of USER_LOGIN_USERNAME_ONLY

UserLoginTestBase::assertFailedLogin in core/modules/user/tests/user.test: Make an unsuccessful login attempt.
UserLoginTestCase::testLoginMethods in core/modules/user/tests/user.test: Test that login credentials work (or not) in different login modes.
user_login in core/modules/user/user.module: Form builder; the main user login form.
user_login_block in core/modules/user/user.module
user_login_name_validate in core/modules/user/user.module: First phase validation handler for the login form.

core/modules/user/user.module, line 15: Enables the user registration and login system.

define('USER_LOGIN_USERNAME_ONLY', 'username_only')