This is a reserved account for administrative functions at db.etreedb.org.
If a record shows that System added it, it was an automated process. This has happened in bulk on these occations:
Initial population of set lists - Aug. 1999 - Feb. 2000
Copy of archive.org bands, shows, and source information - March 2006
Added by the dbetree Live Music Archive Automated Setlist Parser - Fall 2008
If an audit trail shows System modified it, one of db's administrators changed the data to be more consistent with the rest of the site.