Able to

draft-ietf-quic-transport.md

@@ -3615,7 +3615,7 @@ expected to send every stream octet.  The largest offset delivered on a stream
 MUST be less than 2^62.
 
 QUIC makes no specific allowances for partial reliability or delivery of stream
-data out of order.  Endpoints are expected to deliver stream data to an
+data out of order.  Endpoints MUST be able to deliver stream data to an
 application as an ordered byte-stream.  Delivering an ordered byte-stream
 requires that an endpoint buffer any data that is received out of order, up to
 the advertised flow control limit.