Print out a usage message.
-=item B<-inform> B<DER>|B<PEM>
+=item B<-inform> B<DER>|B<PEM>, B<-outform> B<DER>|B<PEM>
-This specifies the input format. The B<DER> option uses an ASN1 DER encoded
-form compatible with the PKCS#3 DHparameter structure. The PEM form is the
-default format: it consists of the B<DER> format base64 encoded with
-additional header and footer lines.
-
-=item B<-outform> B<DER>|B<PEM>
-
-This specifies the output format, the options have the same meaning and default
-as the B<-inform> option.
+The input format and output format; the default is B<PEM>.
+The object is compatible with the PKCS#3 B<DHparameter> structure.
+See L<openssl(1)/Format Options> for details.
=item B<-in> I<filename>
=head1 NOTES
-PEM format DH parameters use the header and footer lines:
-
- -----BEGIN DH PARAMETERS-----
- -----END DH PARAMETERS-----
-
OpenSSL currently only supports the older PKCS#3 DH, not the newer X9.42
DH.