Difference between standard and proprietary protocols

I noticed that S3 Compatible appear in both standard and proprietary lists. Is there any difference between the two?

I don’t believe so, but I’m not sure why it shows up in both sections!

It’s been in both for at least 6 years, probably more, maybe because S3 grew into a de-facto standard.

I don’t have S3, but a dummy test showed that if I pick the Standard protocols the dropdown choice persists while I edit, but if I save and come back in, it moves to Proprietary section on the dropdown.

With either dropdown line, three-dot menu’s Copy Destination URL to Clipboard, show it’s s3://.
Presumably coming back in looked up that s3 to pick the dropdown to show, but didn’t know which one.
Anybody want to study the JavaScript? If not, I think it’s pretty safe to assume that these work the same.