This DisplayString object is the INDEX column of discoveryTableEntry, meaning it is the unique key an SNMP manager uses to identify a single row in the discoveryTable of discovered network devices. Because the MIB's own description only says 'Character string value', the field's real content is the name or label assigned to a discovered device or discovery record, distinguishing one table row from another. For example, a walk of discoveryTable would return one entry value per discovered host, each pairing with that row's discoveryipaddr and discoveryOID.