diff --git a/content/u/blog/when-does-ripe-run-out-of-ipv4-addresses/contents.lr b/content/u/blog/when-does-ripe-run-out-of-ipv4-addresses/contents.lr
index 7a13de6..ac7b21f 100644
--- a/content/u/blog/when-does-ripe-run-out-of-ipv4-addresses/contents.lr
+++ b/content/u/blog/when-does-ripe-run-out-of-ipv4-addresses/contents.lr
@@ -33,13 +33,21 @@ date.
 ## Guesses
 
 * [@zajdee](https://twitter.com/zajdee/status/1182236698266275846) 2019-11-15
-* [@pb_double](https://twitter.com/pb_double/status/1182236265233752064):
+* [@pb_double](https://twitter.com/pb_double/status/1182236265233752064)
   2019-11-27 0610 UTC (very precise!)
 * [@agowa338](https://twitter.com/agowa338/status/1182236572047101952) 2019-11-28
-* [@ReplicaJune](https://twitter.com/ReplicaJune/status/1182235564180942849):
+* [@ReplicaJune](https://twitter.com/ReplicaJune/status/1182235564180942849)
   2019-12-12
+* [@Mac_S13](https://twitter.com/Mac_S13/status/1182242286714970113)
+  2019-12-24 (a Christmas present?)
 
 ## Want to guess?
 
 Just follow [@ungleich](https://twitter.com/ungleich) on Twitter
 and post your guess as [a reply to our tweet](https://twitter.com/ungleich/status/1182234419102388224).
+
+Rules are:
+
+* You cannot use the same date somebody else already guessed
+* You can only guess once
+* You can only guess until 2019-10-13-2359 UTC