Addressed comments by @jyasskin in issue w3c#270

index.bs

@@ -1640,7 +1640,9 @@ ceremony, a [RP] MUST proceed as follows:
 8. Verify that the RP ID hash in |authData| is indeed the SHA-256 hash of the RP ID expected by the RP.
 
 9. Determine the attestation statement format by performing an USASCII case-sensitive match on |fmt| against the set of
-    WebAuthn Attestation Statement Format Identifier values in the IANA registry of the same name [[!WebAuthn-Registries]].
+    supported WebAuthn Attestation Statement Format Identifier values.
+    The up-to-date list of registered WebAuthn Attestation Statement Format Identifier values
+    is maintained in the in the IANA registry of the same name [[!WebAuthn-Registries]].
 
 10. Verify that |attStmt| is a correct, validly-signed attestation statement, using the attestation statement format |fmt|'s
     verification procedure given [=authenticator data=] |authData| and the [=hash of the serialized client data=] computed in
@@ -2422,7 +2424,7 @@ prompt string, intended for display on a trusted device on the authenticator.
 :: A single [=UTF-8 encoded=] string prompt.
 
 : Client processing
-:: None, except default forwarding of client argument to authenticator argument.
+:: None, except creating the authenticator argument from the client argument.
 
 : Client data
 :: Returns the authenticator data string as JSON string
@@ -2455,7 +2457,7 @@ allows authenticators without a font rendering engine to be used and also suppor
     ```
 
 : Client processing
-:: None, except default forwarding of client argument to authenticator argument.
+:: None, except creating the authenticator argument from the client argument.
 
 : Client data
 :: Returns the base64url encoding of the authenticator data value as a JSON string
@@ -2526,7 +2528,7 @@ This [=registration extension=] enables the [RP] to determine which extensions t
 :: The Boolean value `true` to indicate that this extension is requested by the [RP].
 
 : Client processing
-:: None, except default forwarding of client argument to authenticator argument.
+:: None, except creating the authenticator argument from the client argument.
 
 : Client data
 :: Returns the list of supported extensions as a JSON array of extension identifier strings
@@ -2553,7 +2555,7 @@ This [=registration extension=] and [=authentication extension=] enables use of
 :: The Boolean value `true` to indicate that this extension is requested by the [RP].
 
 : Client processing
-:: None, except default forwarding of client argument to authenticator argument.
+:: None, except creating the authenticator argument from the client argument.
 
 : Client data
 :: Returns a JSON string containing the base64url encoding of the authenticator data
@@ -2609,7 +2611,7 @@ party.
 :: The Boolean value `true` to indicate that this extension is requested by the [RP].
 
 : Client processing
-:: None, except default forwarding of client argument to authenticator argument.
+:: None, except creating the authenticator argument from the client argument.
 
 : Client data
 :: Returns a JSON object that encodes the location information in the authenticator data as a Coordinates value,
@@ -2662,7 +2664,7 @@ This [=registration extension=] and [=authentication extension=] enables use of
 :: The Boolean value true to indicate that this extension is requested by the WebAuthn Relying Party.
 
 : Client processing
-:: None, except default forwarding of client argument to authenticator argument.
+:: None, except creating the authenticator argument from the client argument.
 
 : Client data
 :: Returns a JSON array of 3-element arrays of numbers that encodes the factors in the authenticator data