For systems where there are multiple possible matches, if the username field is already filled out on the form, then use the matching password to fill out the password field. This would be particularly useful where the autofill hotkey is used.
This is useful where multiple accounts are available for the same service. Putting in “alice” as the username on “login.foo.com”, then pressing the autofill hotkey, the system should query for login.foo.com credentials where username == “alice”. If no username match, then fallback to existing logic.
Using a desktop browser with a conventional username / password prompt, GitHub in this example, if I have multiple logins saved for github such as username: personal1 and another username: acmecorp1 if I do autofill it selects the 1st matching login. However if I partial complete the form, or even partially complete a username field, it should have enough smarts to choose the “best” matching login and not just the first - for example I type acmecorp1 into username then hit ctrl+shift+l, or even just ‘a’ should be enough to discrimination, that I want the second matching login, however it fills with the first.