on one of my sites I have 2 options listed in the Login and Registrations page, Standard and Google:

but on others, I have more options with 2 Standard methods:

Just wondering why that is. I've only ever used Standard, Twitter and Google.

Older versions had all login methods listed by default, and during the upgrade, they were converted as disabled. You can safely delete them, but leaving them there disabled won't cause any issues, either.

Interesting, thanks TB!