diff --git a/ietf-voucher-request.yang b/ietf-voucher-request.yang
index d027cd3..63e1ab6 100644
--- a/ietf-voucher-request.yang
+++ b/ietf-voucher-request.yang
@@ -202,11 +202,17 @@ module ietf-voucher-request {
         leaf agent-signed-data {
           type binary;
           description
-            "The agent-signed-data field contains a JOSE [RFC7515]
-             object provided by the Registrar-Agent to the Pledge.
+            "The agent-signed-data field contains a data artifact provided
+            by the Registrar-Agent to the Pledge for inclusion into the
+            voucher request.
 
-             This artifact is signed by the Registrar-Agent
-             and contains a copy of the pledge's serial-number.";
+            This artifact is signed by the Registrar-Agent and contains
+            data, which can be verified by the pledge and the registrar.
+            This data contains the pledge's serial-number and a created-on
+            information of the agent-signed-data.
+
+	    The format is intentionally defined as binary to allow
+	    the document using this leaf to determine the encoding.";
         }
 
         leaf agent-provided-proximity-registrar-cert {