diff --git a/zip-0221.rst b/zip-0221.rst
index 3816251d..347df650 100644
--- a/zip-0221.rst
+++ b/zip-0221.rst
@@ -1,7 +1,7 @@
 ::
 
-  ZIP: 0221
-  Title: FlyClient Zcash SPV
+  ZIP: 221
+  Title: FlyClient - Consensus-Layer Changes
   Owners: Jack Grigg <jack@electriccoin.co>
   Original-Authors: Ying Tong
                     James Prestwich
@@ -40,17 +40,11 @@ described in ZIP 200. [#zip-0200]_
 Abstract
 ========
 
-This ZIP specifies modifications to be made to the Zcash block header format to include
-Merkle Mountain Range (MMR) commitments. Sapling (NU2) introduced the
-``hashFinalSaplingRoot`` field to Zcash headers. This ZIP replaces the
-``hashFinalSaplingRoot`` commitment with ``hashChainHistoryRoot``, which is the root of an
-MMR that commits to many features of the chain's history, including all information
-present in ``hashFinalSaplingRoot``.
-
-The MMR that produces the root provides a number of benefits to light clients, and enables
-future specification of the FlyClient protocol [#FlyClient]_. This ZIP specifies only
-consensus-layer changes. It does not provide any specification about the FlyClient
-protocol's operation.
+This ZIP specifies modifications to the Zcash block header semantics and consensus rules
+in order to support the probabilistic verification FlyClient protocol [#FlyClient]_. The
+``hashFinalSaplingRoot`` commitment in the block header is replaced with a commitment to
+the root of a Merkle Mountain Range (MMR), that in turn commits to various features of the
+chain's history, including the Sapling commitment tree.
 
 
 Background