Determines whether this call details entry is used in a search of call details for an incoming call based on the
contents of the user-user information in the incoming SETUP message. The value 'off' means that this call details
entry is not used in the search. The value 'local' means that the call details entry is used in the search and
the user-user information is compared with the call details entry name. The value 'remote' means that the call
details entry is used in the search and the user-user information is compared with the call details entry remote
name. A number of searches are carried out until a matching call is found. First a search against the called
subaddress in the SETUP message, then a search against the user-user information in the SETUP message, then a
search against the calling number information in the SETUP message, then a search for any call that is configured
to respond to any incoming call.