cc: Client certificate
+pgp: PGP encryption key
+pw: Password only
+smime: S/MIME certificate
+snmp: SNMP
+up: User name + password
+usk: User name + SSH key
++ 'file' means to store the user in the database. +
++ The element is called SOURCES for historic reasons. Only one SOURCE is allowed. +
+cc: Client certificate
+pgp: PGP encryption key
+pw: Password only
+smime: S/MIME certificate
+snmp: SNMP
+up: User name + password
+usk: User name + SSH key
++ 'file' means to store the user in the database. +
++ The element is called SOURCES for historic reasons. Only one SOURCE is allowed. +
+