I believe the res agents must code the following in the PNR's "E-Ticket Remarks" section:
eg. SWU1234567891234AMSATL03MAR13/SWU9876543219876ATLAMS09MAR13

explained: SWU[Cert No.][Origin][Dest][Day][Month][Year]/Repeat As Necessary

Then the agent must document the PNR using CMS canned OSI remark "PSGR USING SM SYSTEMWIDE UPGRADE"

I guess that's a very jargon-y explanation, but that is the process afaik from a res perspective.