diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/ForwardedRoomKeyContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/ForwardedRoomKeyContent.kt
index cf8652352c..ea5fb26d83 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/ForwardedRoomKeyContent.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/ForwardedRoomKeyContent.kt
@@ -20,28 +20,53 @@ import com.squareup.moshi.JsonClass
 
 /**
  * Class representing the forward room key request body content
+ * Ref: https://matrix.org/docs/spec/client_server/latest#m-forwarded-room-key
  */
 @JsonClass(generateAdapter = true)
 data class ForwardedRoomKeyContent(
-
+        /**
+         * Required. The encryption algorithm the key in this event is to be used with.
+         */
         @Json(name = "algorithm")
         val algorithm: String? = null,
 
+        /**
+         * Required. The room where the key is used.
+         */
         @Json(name = "room_id")
         val roomId: String? = null,
 
+        /**
+         * Required. The Curve25519 key of the device which initiated the session originally.
+         */
         @Json(name = "sender_key")
         val senderKey: String? = null,
 
+        /**
+         * Required. The ID of the session that the key is for.
+         */
         @Json(name = "session_id")
         val sessionId: String? = null,
 
+        /**
+         * Required. The key to be exchanged.
+         */
         @Json(name = "session_key")
         val sessionKey: String? = null,
 
+        /**
+         * Required. Chain of Curve25519 keys. It starts out empty, but each time the key is forwarded to another device,
+         * the previous sender in the chain is added to the end of the list. For example, if the key is forwarded
+         * from A to B to C, this field is empty between A and B, and contains A's Curve25519 key between B and C.
+         */
         @Json(name = "forwarding_curve25519_key_chain")
         val forwardingCurve25519KeyChain: List<String>? = null,
 
+        /**
+         * Required. The Ed25519 key of the device which initiated the session originally. It is 'claimed' because the
+         * receiving device has no way to tell that the original room_key actually came from a device which owns the
+         * private part of this key unless they have done device verification.
+         */
         @Json(name = "sender_claimed_ed25519_key")
         val senderClaimedEd25519Key: String? = null
 )