How to move from OData V4.0 to V4.01 other than with a big bang?

[HeikoTheissen]

Consider an application stack (from UI to server) that uses the OData V4.0 protocol. It seems impossible to introduce some of the V4.01 features into the stack without introducing everything at once. Some features can be controlled with capabilities annotations, but not nearly all.

This would not be a problem if UI and service were developed together and know each other. But an application stack often contains a UI framework that generically handles OData features and needs to know which are supported.

If the service responds with OData-Version: 4.01, can the UI assume that the service understands all 4.01 features?

If the service responds with OData-Version: 4.0, how can the server advertise the 4.01 features that it does understand?

[ralfhandl]

The service should annotate which (new) features it supports, independent of the OData version it responds with.

And I thought we had annotations for all major new features and tracked that in a Jira issue (which I can't find).

[HeikoTheissen]

What does "supported" mean in OData-Protocol, section 8.2.7?

f specified, the service MUST generate a response with the greatest supported OData-Version less than or equal to the specified OData-MaxVersion or fail the request with an appropriate error.

Supported for that request, or supported in general? But no service will ever support 4.0x in general, will it?