The Capabilities.SupportedFormat term is not clear about if it covers the metadata's media format

[dingeins]

The current specification is:

<Term Name="SupportedFormats" Type="Collection(Edm.String)">
  <Annotation Term="Core.Description" String="Media types of supported formats, including format parameters" />
  <Annotation Term="Core.IsMediaType" />
</Term>

It's not clear if only the metadata supports XML, application/xml should be included into the annotation:

  <Annotation Term="Org.OData.Capabilities.V1.SupportedFormats">
    <Collection>
     <String>application/json; odata.metadata=minimal; odata.streaming=true</String>
     <String>application/json; odata.metadata=minimal; odata.streaming=false</String>
     <String>application/json; odata.metadata=minimal</String>
     <String>application/json; odata.metadata=full; odata.streaming=true</String>
     <String>application/json; odata.metadata=full; odata.streaming=false</String>
     <String>application/json; odata.metadata=full</String>
     <String>application/json; odata.metadata=none; odata.streaming=true</String>
     <String>application/json; odata.metadata=none; odata.streaming=false</String>
     <String>application/json; odata.metadata=none</String>
     <String>application/json; odata.streaming=true</String>
     <String>application/json; odata.streaming=false</String>
     <String>application/json</String>
     <String>application/xml</String>
    </Collection>
  </Annotation>
</Annotations>

And in future when JSON is also supported for metadata, a new term like Capabilities.SupportedFormatForMetadata might be helpful for avoid confusion.

[ralfhandl]

The term only refers to data, not $metadata. Unfortunately this is not reflected in the vocabulary, only in the preliminary discussion in https://issues.oasis-open.org/browse/ODATA-248.

I've created https://issues.oasis-open.org/browse/ODATA-805 to track this proposal.