+Print extra information about the operations being performed.
+
+=item B<-auth_level level>
+
+Set the certificate chain authentication security level to B<level>.
+The authentication security level determines the acceptable signature and
+public key strength when verifying certificate chains.
+For a certificate chain to validate, the public keys of all the certificates
+must meet the specified security B<level>.
+The signature algorithm security level is enforced for all the certificates in
+the chain except for the chain's I<trust anchor>, which is either directly
+trusted or validated by means other than its signature.
+See L<SSL_CTX_set_security_level(3)> for the definitions of the available
+levels.
+The default security level is -1, or "not set".
+At security level 0 or lower all algorithms are acceptable.
+Security level 1 requires at least 80-bit-equivalent security and is broadly
+interoperable, though it will, for example, reject MD5 signatures or RSA keys
+shorter than 1024 bits.
+
+=item B<-verify_depth num>
+
+Limit the certificate chain to B<num> intermediate CA certificates.
+A maximal depth chain can have up to B<num+2> certificates, since neither the
+end-entity certificate nor the trust-anchor certificate count against the
+B<-verify_depth> limit.
+
+=item B<-verify_email email>
+
+Verify if the B<email> matches the email address in Subject Alternative Name or
+the email in the subject Distinguished Name.
+
+=item B<-verify_hostname hostname>
+
+Verify if the B<hostname> matches DNS name in Subject Alternative Name or
+Common Name in the subject certificate.
+
+=item B<-verify_ip ip>
+
+Verify if the B<ip> matches the IP address in Subject Alternative Name of
+the subject certificate.
+
+=item B<-verify_name name>
+
+Use default verification policies like trust model and required certificate
+policies identified by B<name>.
+The trust model determines which auxiliary trust or reject OIDs are applicable
+to verifying the given certificate chain.
+See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
+utility.
+Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
+B<ssl_client>, B<ssl_server>.
+These mimics the combinations of purpose and trust settings used in SSL, CMS
+and S/MIME.
+As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
+specified, so the B<-verify_name> options are functionally equivalent to the
+corresponding B<-purpose> settings.
+
+=item B<-x509_strict>
+
+For strict X.509 compliance, disable non-compliant workarounds for broken
+certificates.
+
+=item B<-show_chain>
+
+Display information about the certificate chain that has been built (if
+successful). Certificates in the chain that came from the untrusted list will be
+flagged as "untrusted".