Per-service configuration files enable you to customize the environment for a specific service. For example, a service might require special privileges that are not available to the general user. Using the language described in the doconfig(3NSL) man page, you can write a script that grants or limits such special privileges to a particular service offered through a particular port monitor.
The per-service configuration might override defaults provided by higher-level configuration scripts. For example, the per-service configuration script might specify a set of STREAMS modules other than the default set.