regenerate docs
diff --git a/doc/html/openssl-x509.html b/doc/html/openssl-x509.html
index 8787e04..58f455b 100644
--- a/doc/html/openssl-x509.html
+++ b/doc/html/openssl-x509.html
@@ -91,6 +91,7 @@
                  YYYYMMDDhhmmss+hhmm
                  YYYYMMDDhhmmss-hhmm
 </pre></dl>
+If no value exists for this field, <code>None</code> is returned.
 </dl>
 
 <P>
@@ -103,6 +104,7 @@
                  YYYYMMDDhhmmss+hhmm
                  YYYYMMDDhhmmss-hhmm
 </pre></dl>
+If no value exists for this field, <code>None</code> is returned.
 </dl>
 
 <P>