Update reference/nats-protocol/nats-protocol/README.md

tighten verbage

Co-authored-by: Byron Ruth <[email protected]>

reference/nats-protocol/nats-protocol/README.md

@@ -180,7 +180,7 @@ To publish an empty message to subject NOTIFY:
 
 The `HPUB` message is the same as `PUB` but extends total message payload to include NATS headers. Note that the payload itself is optional. To omit the payload, set the total message size to the same as the headers size. Note that the trailing CR+LF is still required.
 
-NATS headers are similar in semantic to HTTP headers as `name: value` pairs. Multi-value headers are allowed. Headers can be mixed case and NATS will preserve case between message publisher and message receiver(s).  See also [ADR-4 NATS Message Headers](https://github.com/nats-io/nats-architecture-and-design/blob/main/adr/ADR-4.md).
+NATS headers are similar, in structure and semantics, to HTTP headers as `name: value` pairs including supporting multi-value headers. Headers can be mixed case and NATS will preserve case between message publisher and message receiver(s).  See also [ADR-4 NATS Message Headers](https://github.com/nats-io/nats-architecture-and-design/blob/main/adr/ADR-4.md).
 
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