In a sidenote in WS-Discovery it is written in regard the MetadataVersion:
/s:Envelope/s:Body/d:Hello/d:MetadataVersion
Incremented by a positive value (>= 1) whenever there is a change in the metadata of the Target Service. If a Target Service goes down and comes back up again, this value MAY be incremented but MUST NOT be decremented (see Section 7 Application Sequencing). Metadata includes, but is not limited to, ../d:Types and ../d:Scopes. By design, this value MAY be used by the C
see https://docs.oasis-open.org/ws-dd/discovery/1.1/os/wsdd-discovery-1.1-spec-os.html#_Toc234231821.
Since many stacks at the PAT 22 had not implemented it correctly (good practise: use a timestamp) it was desired to mention / require it explicitly in SDPi.
In a sidenote in WS-Discovery it is written in regard the MetadataVersion:
/s:Envelope/s:Body/d:Hello/d:MetadataVersion
Incremented by a positive value (>= 1) whenever there is a change in the metadata of the Target Service. If a Target Service goes down and comes back up again, this value MAY be incremented but MUST NOT be decremented (see Section 7 Application Sequencing). Metadata includes, but is not limited to, ../d:Types and ../d:Scopes. By design, this value MAY be used by the C
see https://docs.oasis-open.org/ws-dd/discovery/1.1/os/wsdd-discovery-1.1-spec-os.html#_Toc234231821.
Since many stacks at the PAT 22 had not implemented it correctly (good practise: use a timestamp) it was desired to mention / require it explicitly in SDPi.