Reverse condition around MUST

draft-ietf-httpbis-connect-tcp.md

@@ -149,7 +149,7 @@ Clients SHOULD assume that all proxy resources generated by a single template sh
 
 When using the "connect-tcp" Upgrade Token, templated TCP proxies do not use the Capsule Protocol {{!RFC9297}}.  Clients MAY request use of the Capsule Protocol by offering the Upgrade Token "connect-tcp-capsule" instead.  When offering or accepting the "connect-tcp-capsule" Upgrade Token, clients and servers SHOULD including a "Capsule-Protocol: ?1" header to facilitate processing by intermediaries.
 
-Clients of this specification MAY implement "connect-tcp", "connect-tcp-capsule", or both.  Accordingly, templated TCP proxy servers for arbitrary clients MUST implement both Upgrade Tokens.
+Clients of this specification MAY implement "connect-tcp", "connect-tcp-capsule", or both.  Accordingly, a templated TCP proxy server MUST implement both Upgrade Tokens unless its use is restricted to a subset of compatible clients.
 
 When using "connect-tcp-capsule", TCP payload data is sent in the payload of a new Capsule Type named DATA ({{data-capsule}}).  The ordered concatenation of DATA capsule payloads represents the main payload data stream in any protocol where this is well-defined.  Intermediaries MAY split or merge DATA capsules.  Endpoints MAY indicate a TCP connection error by sending an incomplete DATA capsule, as an alternative to using TCP, TLS, or HTTP stream errors.
 
@@ -216,15 +216,16 @@ Templated TCP proxies can make use of standard HTTP gateways and path-routing to
 
 # IANA Considerations
 
-## New Upgrade Token
+## New Upgrade Tokens
 
-IF APPROVED, IANA is requested to add the following entry to the HTTP Upgrade Token Registry:
+IF APPROVED, IANA is requested to add the following entries to the HTTP Upgrade Token Registry:
 
-* Value: "connect-tcp"
-* Description: Proxying of TCP payloads
-* Reference: (This document)
+| Value | Description | Reference |
+| ----- | ----------- | --------- |
+| "connect-tcp" | Proxying of TCP payloads | (This document) |
+| "connect-tcp-capsule" | Proxying of TCP payloads in HTTP Capsules | (This document) |
 
-For interoperability testing of this draft version, implementations SHALL use the value "connect-tcp-05".
+For interoperability testing of this draft version, implementations SHALL use the values "connect-tcp-06" and "connect-tcp-capsule-06.
 
 ## New MASQUE Default Template {#iana-template}