diff --git a/draft-ietf-sidrops-8210bis.xml b/draft-ietf-sidrops-8210bis.xml
index de88d16..54e7f79 100644
--- a/draft-ietf-sidrops-8210bis.xml
+++ b/draft-ietf-sidrops-8210bis.xml
@@ -10,7 +10,7 @@
 <?rfc compact="yes"?>
 <?rfc subcompact="no"?>
 
-<rfc category="std" docName="draft-ietf-sidrops-8210bis-03" updates="8210" ipr="trust200902" consensus="yes">
+<rfc category="std" docName="draft-ietf-sidrops-8210bis-04" updates="8210" ipr="trust200902" consensus="yes">
 
   <front>
 
@@ -65,7 +65,7 @@
     <section anchor="Intro" title="Introduction">
       <t>
         In order to verifiably validate the origin Autonomous Systems
-        (ASes) and AS paths of BGP announcements, routers need a
+        (ASs) and AS paths of BGP announcements, routers need a
         simple but reliable mechanism to receive cryptographically
         validated Resource Public Key Infrastructure (RPKI)
         <xref target="RFC6480"/> prefix origin data and router keys
@@ -967,54 +967,65 @@
 ~-------------------------------------------~
           </artwork>
         </figure>
-	<t>The ASPA PDU is to support <xref
-	target="I-D.ietf-sidrops-aspa-profile"/>.  An ASPA PDU
-	represents one single customer AS and one or more provider ASs
-	for a particular Address Family.  Receipt of an ASPA PDU
-	announcement when the router already has an ASPA PDU with the
-	same Customer Autonomous System Number and the same Address
-	Family (see Flags field), replaces the previous one.  This is to
-	avoid a race condition when a BGP announcement is received
-	between an withdrawn PDU and a new announced PDU.  Therefore, the
-	cache MUST deliver entire data of an ASPA record in a single
-	ASPA PDU.
+	
+	<t>
+	  The ASPA PDU is to support <xref
+	  target="I-D.ietf-sidrops-aspa-profile"/>.  An ASPA PDU
+	  represents one single customer AS and its provider ASs for a
+	  particular Address Family.  Receipt of an ASPA PDU
+	  announcement when the router already has an ASPA PDU with the
+	  same Customer Autonomous System Number and the same Address
+	  Family (see Flags field), replaces the previous one.  This is
+	  to avoid a race condition when a BGP announcement is received
+	  between an withdrawn PDU and a new announced PDU.  Therefore,
+	  the cache MUST deliver entire data of an ASPA record in a
+	  single ASPA PDU.
 	</t>
-	<t>The router should only see one ASPA for a particular Customer
-	Autonomous System Number active at any time.  This may place a
-	burden on the cache to merge multiple ASPA records it has
-	received from the global RPKI into one ASPA PDU.
+	
+	<t>
+	  The router should see at most one ASPA from a cache for a
+	  particular Customer Autonomous System Number active at any
+	  time.  As a number of conditions in the global RPKI may
+	  present multiple valid ASPA objects for a single customer to a
+	  particular RP cache, this places a burden on the cache to
+	  merge multiple ASPA records it has received from the global
+	  RPKI into one ASPA PDU.
 	</t>
+	
         <t>
           The Flags field is defined as follows:</t>
     <figure>
       <artwork>
     Bit     Bit Name
     ----    -------------------
-     0      Announce/Withdraw (ann == 1, with == 0)
-     1      AFI (IPv4 == 0, IPv6 == 1)
-     2-7    Reserved, must be zero
+     0      AFI (IPv4 == 0, IPv6 == 1)
+     1-7    Reserved, must be zero
        </artwork>
     </figure>
+    
+        <t>
+          The Provider AS Count is the number of 32-bit Provider
+          Autonomous System Numbers in the PDU.
+        </t>
+	
         <t>
-          The Provider AS Count is the number of Provider Autonomous
-          System Number(s) at the end of the PDU, and MUST be one or
-          more.
-	</t>
-	<t>
           The Customer Autonomous System Number is the 32-bit Autonomous
           System Number of the customer which signed the PDU.  There
           MUST be one and only one ASPA for a Customer Autonomous System
           Number active in the router at any time.
         </t>
-        <t>
-          The Provider AS Count is the number of 32-bit Provider
-          Autonomous System Numbers in the PDU.  It MUST be one or
-          greater.
-        </t>
+	
         <t>
           There are one or more 32-bit Provider Autonomous System Number
           fields; see <xref target="I-D.ietf-sidrops-aspa-profile"/>.
         </t>
+
+	<t>
+	  Receipt of an ASPA PDU with zero providers is an implicit
+	  withdraw of the entire ASPA data for that customer AS from
+	  that cache.
+	</t>
+	
       </section>
         
      </section>