This read-only TruthValue indicates whether a particular DNIS node row can be modified, which is true only when the corresponding map name in cvDnisMappingTable has no filename set in cvDnisMappingUrl, and false (read only) whenever a mapping file governs that map. Administrators use it to understand whether a given DNIS node was manually configured or is being centrally managed via an imported mapping file. For example, if an admin tries to edit a DNIS node and finds this object is false, they know they must instead update the source mapping file rather than the node directly.