PGP has a number of user-settable parameters that can be defined in a special PGP configuration text file called config.txt, in the directory pointed to by the shell environmental variable PGPPATH. Having a configuration file enables the user to define various flags and parameters for PGP without the burden of having to always define these parameters in the PGP command line.
In the interest of complying with local operating system file naming conventions, for Unix systems this configuration file may also be named .pgprc, and on MSDOS systems it may also be named pgp.ini.
With these configuration parameters, for example, you can control where PGP stores its temporary scratch files, or you can select what foreign language PGP will use to display its diagnostics messages and user prompts, or you can adjust PGP's level of skepticism in determining a key's validity based on the number of certifying signatures it has.
For more details on setting these configuration parameters, see the appropriate section of the PGP User's Guide, Special Topics volume.