diff --git a/index.d.ts b/index.d.ts
index ba7536e..bf504a9 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -11,7 +11,7 @@ export interface Event<K extends number = number> {
   pubkey: string;
   content: string;
   created_at: number;
-  /** See also [NIP-03](https://github.com/nostr-protocol/nips/blob/master/03.md). */
+  /** @deprecated Use kind 1040 (NIP-03) instead. */
   ots?: string;
 }
 
@@ -37,7 +37,7 @@ export interface EventParameters<K extends number = number> {
   pubkey?: string;
   content: string;
   created_at?: number;
-  /** See also [NIP-03](https://github.com/nostr-protocol/nips/blob/master/03.md). */
+  /** @deprecated Use kind 1040 (NIP-03) instead. */
   ots?: string;
 }
 
@@ -225,6 +225,16 @@ export namespace Tag {
     marker?: EventMarker
   ];
 
+  /**
+   * OpenTimestamps proof.
+   *
+   * See also [NIP-03](https://github.com/nostr-protocol/nips/blob/master/03.md).
+   */
+  export type block = [
+    blockHeight: string,
+    blockHash: string,
+  ];
+
   /**
    * Associate the tagged Kind0 (Metadata) Event with the specified external identity.
    *