Part numbers are the available in the Announcement Letter for the Service or Release. I went to the Offering Site, and did a search. I entered “IBM Connections Cloud S1” and selected Announcement Letter. I clicked Search
A quick link to my search is here .
I scroll down and find the entry that corresponds to the Announcement letter for my geography and purpose. I click on the entry.
I scroll down and find my part numbers.
Bam, I can call the BSS API mentioned above with the part number, and entitle a user for that part number.