Two-factor auth selecting focus and suddenly seeing a dropdown of old, worthless 6-digit numbers comes to mind.
The autocomplete attribute is very extensive.
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes...
I don't recall the service, but one employer of mine had both the suggestions for the MFA token, and as an added bonus, the browser would attempt to correct the "typo" in my username.