When you use the pkgadd -a command, the pkgadd command consults a special administration file for information about how the installation should proceed. Normally, pkgadd performs several checks and prompts the user for confirmation before actually adding the specified package. You can, however, create an administration file that indicates to pkgadd it should bypass these checks and install the package without user confirmation.
The pkgadd command, by default, looks in the current working directory for an administration file. If pkgadd doesn't find an administration file in the current working directory, pkgadd looks in the /var/sadm/install/admin directory for the specified administration file. The pkgadd command also accepts an absolute path to the administration file.
Use administration files judiciously. You should know where a package's files are installed and how a package's installation scripts run before using an administration file to avoid the checks and prompts pkgadd normally provides.
mail= instance=overwrite partial=nocheck runlevel=nocheck idepend=nocheck rdepend=nocheck space=nocheck setuid=nocheck conflict=nocheck action=nocheck basedir=default
Besides using administration files to avoid user interaction when adding packages, you can use them in several other ways. For example, you can use an administration file to quit a package installation (without user interaction) if there's an error or to avoid interaction when removing packages with the pkgrm command.
You can also assign a special installation directory for a package. (It would make sense to do this if you wanted to maintain multiple versions of a package on a system.) To do this, set an alternate base directory in the administration file (using the basedir keyword), which specifies where the package will be installed. See admin(4) for more information.