In any record that we get through the MARC record service, the 001 and the 035 should have the SSJ# already. If you are importing a record from Connexion or creating a brief record, and you expect the record to be overlaid by the MARC record service, you need to add the SSJ# to the Title Control Number, 001, & 035.
Title Control Number
The MARC record service loads could match on the Title Control Number (i.e., FlexKey). In order for MARC record updates to correctly overlay without creating duplicates, the SSJ# needs to be in this field.
MARC record service loads look for the SSJ# in the Title Control Number field first and then the 001 as a secondary check, so we need to put the SSJ# here too.
The TRLN union catalog (Search TRLN) is rolling up based on the 035, so we need to put the SSJ# in the 035, formatted as follows.
If, for some reason, you are working with a brief bib record that will be displaying publicly, you should also add the SSJ in the 035. This probably won't happen often, if at all.
If you add an SSJ to an existing full record, add the ItemCat 3 of "360MARC". This ItemCat isn't getting added when SSJs are added to existing records because new item records are not created under that process. You do not need to add this ItemCat to brief bibs, as items are created for those and the 360MARC ItemCat will be added during that process.
The documentation above only pertains to SSJ records. For non-SSJ records (i.e., records that you do not expect to be overlaid by the MARC record service, such as database records), you can just accept the title control, 001, and 035 as is. No edits are necessary.