Completely ignore unknown hspow-params

1 files changed, 7 insertions, 5 deletions

diff --git a/spec/rend-spec/hsdesc-encrypt.md b/spec/rend-spec/hsdesc-encrypt.md
index 531c70a..3d2117e 100644
--- a/spec/rend-spec/hsdesc-encrypt.md
+++ b/spec/rend-spec/hsdesc-encrypt.md
@@ -255,17 +255,19 @@ list of intro points etc. The plaintext has the following format:
      "pow-params" SP scheme SP seed-b64 SP suggested-effort
                   SP expiration-time NL
 
-      [At most once per "scheme"]
-
       If present, this line provides parameters for an optional proof-of-work
       client puzzle. A client that supports an offered scheme can include a
       corresponding solution in its introduction request to improve priority
       in the service's processing queue.
 
       Only scheme `v1` is currently defined.
-      Unknown schemes found in a descriptor should be ignored by clients.
-      Other schemes may have a different format (in the parts of the
-      Item after the "scheme"; this could even include an Object).
+      It may appear only once.
+
+      Unknown schemes found in a descriptor must be completely ignored:
+      future schemes might have a different format (in the parts of the
+      Item after the "scheme"; this could even include an Object); and
+      future schemes might allow repetition, and might appear in any order.
+
       Introduced in tor-0.4.8.1-alpha.
 
         scheme: The PoW system used. We call the one specified here "v1".