This value, when true, indicates that the associated multicast scope name in its given language should be used by applications as a fallback whenever no name is available in their preferred language, and defaults to false. An admin sets this on the scope-name entry meant to serve as the universal fallback label shown to end users when allocating multicast addresses within that scope. For example, marking the English-language name for an organization's local multicast scope as ipMRouteScopeNameDefault=true ensures applications display it when no localized name exists.