+=item B<-precert>
+
+A poison extension will be added to the certificate, making it a
+"pre-certificate" (see RFC6962). This can be submitted to Certificate
+Transparency logs in order to obtain signed certificate timestamps (SCTs).
+These SCTs can then be embedded into the pre-certificate as an extension, before
+removing the poison and signing the certificate.
+
+This implies the B<-new> flag.
+