}

    #
    # NOTE: The regular expression pattern used when attempting to verify
    #       that OpenPGP successfully imported one or more keys.  This must
    #       be configured according to the implementation of OpenPGP in use.
    #
    variable openPgpImportPattern; # DEFAULT: ^gpg: Total number processed...

    if {![info exists openPgpImportPattern]} then {
      set openPgpImportPattern {^gpg: Total number processed: [1-9]\d*$}
    }

    #
    # NOTE: The command to use when attempting to verify that OpenPGP is
    #       installed locally.  This must be configured according to the
    #       implementation of OpenPGP in use.
    #
    variable openPgpInstalledCommand; # DEFAULT: gpg2 --version

    if {![info exists openPgpInstalledCommand]} then {
      set openPgpInstalledCommand {{${fileName}} --version}
    }

    #
    # NOTE: The regular expression pattern used when attempting to verify
    #       that OpenPGP is installed locally.  This must be configured
    #       according to the implementation of OpenPGP in use.
    #
    variable openPgpInstalledPattern; # DEFAULT: ^gpg \(GnuPG\) 2\.[0123]\.

    if {![info exists openPgpInstalledPattern]} then {
      set openPgpInstalledPattern {^gpg \(GnuPG\) 2\.[0123]\.}
    }

    #
    # NOTE: The command to use when verifying OpenPGP signatures for the
    #       downloaded package scripts.  This must be configured according
    #       to the implementation of OpenPGP in use.
    #