diff --git a/content/momentum/4/index.md b/content/momentum/4/index.md
index b44a1473..d0fc236e 100644
--- a/content/momentum/4/index.md
+++ b/content/momentum/4/index.md
@@ -1,6 +1,6 @@
 ---
 lastUpdated: "09/30/2024"
-title: "Momentum 4.x"
+title: "Momentum 4.x and later"
 description: "Message Systems Inc Copyright 2014-2024 Message Systems Inc Confidential Proprietary Abstract This book documents Momentum 4 Document generated on 2024 Sep 30 Table of Contents Preface 1 Typographical Conventions Used in This Document I Introduction to Momentum 1 Components 2 Life of A Message 3 Roles and Behaviors 4 Licensed..."
 ---
 
@@ -14,7 +14,7 @@ Confidential & Proprietary.
 
 **Abstract**
 
-This book documents Momentum 4.
+This book documents Momentum 4 and later.
 
 Document generated on: 2024-Sep-30
 
diff --git a/content/momentum/4/modules/spf.md b/content/momentum/4/modules/spf.md
index 5f56b4eb..f066df39 100644
--- a/content/momentum/4/modules/spf.md
+++ b/content/momentum/4/modules/spf.md
@@ -104,7 +104,8 @@ Set the default rule for a domain not implementing SPF. The default behavior is
 
 _Introduced in Momentum 5.0._
 
-Postpones the SPF check until the `RCPTTO` phase. This might be useful when the received message is accepted by a relay webhook that does not perform a SPF validation.
+Postpones the SPF check until the `RCPTTO` phase. This might be useful to allow SPF validation based
+on `RCPTTO` address.
 
 </dd>
 
diff --git a/content/momentum/navigation.yml b/content/momentum/navigation.yml
index dba66c3f..5ff45f38 100644
--- a/content/momentum/navigation.yml
+++ b/content/momentum/navigation.yml
@@ -1,5 +1,5 @@
 - link: /momentum/4
-  title: Momentum 4.x
+  title: Momentum 4.x and later
   items:
     - link: /momentum/4/4-preface
       title: Preface