The value n is the node name for this computer, and has many uses:
The node name to be sent to the ECP network server, so that the server can identify the client
The node name for a unique $JOB value. This is useful when using $JOB to index globals accessed by more than one networked system.
Certain forms of the $SYSTEM function return this node name concatenated with the Caché instance name, as nodename:instancename. This concatenated string is recorded in Audit files.
The default is blank. If no name is provided, Caché reads the computer settings and uses the computer “host name” as the client node name. This can be up to 64 characters long.
On the page System Administration > Configuration > Additional Settings > Startup, in the CliSysName row, select Edit. Enter a node name.