-- `--gpg-home` sets the directory for the GnuPG files
-- `--ssh-home` does the same for OpenSSH files
+- `--gpg-home` sets the directory for the GnuPG files (defaults to the
+ value of `GNUPGHOME` or `~/.gnupg`)
+- `--ssh-home` does the same for OpenSSH files (defaults to `~/.ssh`)