++fixes

content/u/blog/draft-for-ipv6-compatibility-check/contents.lr

@@ -27,26 +27,28 @@ maintenance cost has become too high.
 The wording is orientated on
 [RFC2119](https://tools.ietf.org/html/rfc2119).
 
-**This document is an early draft**
+**This document is an early draft**. If you have any comments /
+improvements, please help us to improve it on the [IPv6 Chat](https://IPv6.chat).
 
 ## IPv6 autoconfiguration
 
 All devices must assign themselves an IPv6 address upon receival of a
 router advertisement (compare
-[RFC4861](https://tools.ietf.org/html/rfc4861).
+[RFC4861](https://tools.ietf.org/html/rfc4861)).
 
 ## IPv6 listener
 
 If the device is providing any service, all services **must** bind to
-IPv6 sockets (compare [RFC3493](https://tools.ietf.org/html/rfc3493)).
+IPv6 sockets (compare
+[RFC3493](https://tools.ietf.org/html/rfc3493)). Device **may** also
+bind to IPv4 sockets.
 
 ## Outgoing connections
 
 All devices **must** support requesting **all** resources via IPv6
 only connections. This does not imply that the vendor resource has to
 be reachable by IPv6, as the network operator might provide a NAT64
-service.
-
+service. Devices **may** also try connecting by IPv4.
 
 ## Support for IPv6 DNS servers via router advertisements
 
@@ -70,5 +72,5 @@ reporting, etc.), it **must not** have any hardcoded IPv4 address.
 
 ## Updates
 
-IF a device is receiving software updates, it must be able to receive
+IF a device is receiving software updates, it **must** be able to receive
 software updates in IPv6 only networks.