A link is made from a requirement to a change request

Here is script for www.websequencediagrams.com. I can't persuade the wiki to render this "live", hence the picture which follows is an attachment.

participant "OSLC RM Consumer\nRTC on http://rtc.example.com" as Consumer
participant "OSLC RM Provider\nDOORS on http://doors.example.com" as Provider
note left of Consumer
Consumer is a change request system.  User is working on
change request "/wi/1"
end note
note left of Consumer
Use delegated UI to find requirement that is to be implemented
end note
Consumer->Provider: GET /delegatedUI/projects/SRS Braking
Provider->Consumer: Web application for selecting requirement
Consumer->Consumer: User browses and selects requirement
note left of Consumer
User selects http://doors.example.com/requirement/1
end note
Consumer->Provider: GET /requirement/1\nAccept: application/x-oslc-rm-requirement+xml
Provider->Consumer: <Requirement 1/>
note left of Consumer
<Requirement rdf:about="/requirement/1/>
.. properties ..
</Requirement>
end note
Consumer->Consumer: Update requirement with new link to /wi/1
note left of Consumer
<Requirement rdf:about="/requirement/1/>
.. properties ..
<calm:implementedBy rdf:about="http://rtc.example.com/wi/1"/>
</Requirement>
end note
Consumer->Provider: PUT /requirement/1