+=item B<X509_V_ERR_INVALID_EXTENSION: invalid or inconsistent certificate extension>
+
+A certificate extension had an invalid value (for example an incorrect
+encoding) or some value inconsistent with other extensions.
+
+
+=item B<X509_V_ERR_INVALID_POLICY_EXTENSION: invalid or inconsistent certificate policy extension>
+
+A certificate policies extension had an invalid value (for example an incorrect
+encoding) or some value inconsistent with other extensions. This error only
+occurs if policy processing is enabled.
+
+=item B<X509_V_ERR_NO_EXPLICIT_POLICY: no explicit policy>
+
+The verification flags were set to require and explicit policy but none was
+present.
+
+=item B<X509_V_ERR_DIFFERENT_CRL_SCOPE: Different CRL scope>
+
+The only CRLs that could be found did not match the scope of the certificate.
+
+=item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE: Unsupported extension feature>
+
+Some feature of a certificate extension is not supported. Unused.
+
+=item B<X509_V_ERR_PERMITTED_VIOLATION: permitted subtree violation>
+
+A name constraint violation occurred in the permitted subtrees.
+
+=item B<X509_V_ERR_EXCLUDED_VIOLATION: excluded subtree violation>
+
+A name constraint violation occurred in the excluded subtrees.
+
+=item B<X509_V_ERR_SUBTREE_MINMAX: name constraints minimum and maximum not supported>
+
+A certificate name constraints extension included a minimum or maximum field:
+this is not supported.
+
+=item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: unsupported name constraint type>
+
+An unsupported name constraint type was encountered. OpenSSL currently only
+supports directory name, DNS name, email and URI types.
+
+=item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: unsupported or invalid name constraint syntax>
+
+The format of the name constraint is not recognised: for example an email
+address format of a form not mentioned in RFC3280. This could be caused by
+a garbage extension or some new feature not currently supported.
+
+=item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR: CRL path validation error>
+
+An error occurred when attempting to verify the CRL path. This error can only
+happen if extended CRL checking is enabled.
+