"x-ms-enum" comparing modelAsExtensible vs modelAsString vs oldModelAsString

[Alon Yeshurun (ayeshurun)]

Hi,

Please advise on these 3 options in the "x-ms-enum" field:

1. modelAsExtensible
2. modelAsString
3. oldModelAsString

What are the differences between them?
All of them are supported today? Is there any option that has been deprecated?
Is there a best practice you would recommend?

Thanks