clarify which key again
@@ -30,7 +30,7 @@ the properties:
session belongs to.
- `algorithm`: Required. The encryption algorithm that the key is for.
- `session_id`: Required if `code` is not `m.no_olm`. The ID of the session.
-- `sender_key`: Required. The key of the session creator.
+- `sender_key`: Required. The unpadded base64-encoded device curve25519 key of the session creator.
- `code`: Required. A machine-readable code for why the megolm key was not sent.
Possible values are:
- `m.blacklisted`: the user/device was blacklisted
