Unifier Shell ID element name

Can anyone help identify the name of the element of the Shell ID number that appears in the shell details.  The number is a system generated sequential number that Unifier assigns to new shells.  It is not the Record number.

The only place this is seen is in the job details email address, and, other than Shell ID,  I have not been able to discover any references directly to it's element name in the various Admin documents. 

Although this can be manually changed in job details, My goal is to determine if this number (in the email address) can be replaced with the shells project number via webservices so that each shell is created with the project number in the email address instead of the Shell ID #.