-#XXX: see https://letsencrypt.github.io/acme-spec/
-#XXX: see http://www.rfc-editor.org/rfc/rfc7517.txt
-#XXX: see ietf draft at https://ietf-wg-acme.github.io/acme/
+#XXX: see https://letsencrypt.github.io/acme-spec/ (probably based on https://ietf-wg-acme.github.io/acme/)
+#XXX: see jwk rfc http://www.rfc-editor.org/rfc/rfc7517.txt