Rephrased recommendation regarding sid

draft-irtf-cfrg-cpace.md

@@ -782,7 +782,9 @@ Algorithms for curves other than the ones recommended here can be based on the p
 Secret scalars ya and yb MUST NOT be reused. Values for sid SHOULD NOT be reused since the composability
 guarantees established by the simulation-based proof rely on the uniqueness of session ids {{AHH21}}.
 
-If CPace is used in a concurrent system, it is RECOMMENDED that a unique sid is generated by the higher-level protocol and passed to CPace. One suitable option is that sid is generated by concatenating ephemeral random strings contributed by both parties.
+If the higher-level protocol that integrates CPace is able to establish a unique sid identifier for the communication session,
+it is RECOMMENDED that this is passed to CPace as sid parameter.
+One suitable option for generating sid is concatenation of ephemeral random strings contributed by both parties.
 
 ## Side channel attacks