If the Submission Type for this row is one used by Form Builder 2.0, this column is populated with the name of the submitted form (SUBMISSION_V.FORM_NAME). Otherwise, it is populated with the portlet name from where the submission came (CATCOMDEFINITION.ENTRY_SOURCE).
If you are licensed for CRMs Candidate, Constituent, or Student or campus portal (JICS) Base, this column is populated with the portlet name from where the submission came (CATCOMDEFINITION.ENTRY_SOURCE).