diff --git a/24.md b/24.md
index b21f48e9..51266b05 100644
--- a/24.md
+++ b/24.md
@@ -41,3 +41,4 @@ These tags may be present in multiple event kinds. Whenever a different meaning
 
   - `r`: a web URL the event is referring to in some way
   - `title`: name of [NIP-51](51.md) sets, [NIP-52](52.md) calendar event, [NIP-53](53.md) live event or [NIP-99](99.md) listing
+  - `encrypted`: indicates that the event's content field contains encrypted data. The value should be `nip04` or `nip44` to indicate the encryption method used. If no value is provided, it should be assumed to be `nip04`.
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