diff --git a/63.md b/63.md
index dca0281..b28b1e8 100644
--- a/63.md
+++ b/63.md
@@ -10,7 +10,7 @@ This NIP declares the use of event kind `33012` to represent one or more Nostr f
 
 The `d` tag represents the subscription id and the `filter` tag contains the JSON-stringified (NIP-01)[01.md] filter. 
 
-Supporting relays interpret the tags of this event as if they were submitted in the `REQ` scheme while automatically authenticating the signer. 
+Supporting relays interpret the tags of this event as if they were submitted in the `REQ` scheme while automatically authenticating the signer. The relay MUST delete these events after the connection closes. 
 
 They are submitted to the relay via `EVENT` messages instead of the usual `REQ` message.