diff --git a/index.bs b/index.bs
index 157ecd3e4..a6c246330 100644
--- a/index.bs
+++ b/index.bs
@@ -6794,10 +6794,12 @@ This [=client extension|client=] [=registration extension=] and [=authentication
: Client extension processing
-:: [=map/Set=] [=credentialCreationData/clientExtensionResults=]["{{AuthenticationExtensionsClientOutputs/credProps}}"]["rk"]
- to the value of the |requireResidentKey| parameter that was used in the
- invocation of the [=authenticatorMakeCredential=]
- operation.
+:: 1. If processed during a [=registration ceremony=]:
+ 1. Set {{CredentialPropertiesOutput/rk}} to the value of the |requireResidentKey| parameter that was used in the
+ invocation of the [=authenticatorMakeCredential=]
+ operation.
+ 1. Set {{CredentialPropertiesOutput/authenticatorDisplayName}} as described in its definition, using some client-specific procedure.
+ If no suitable value is found, let {{CredentialPropertiesOutput/authenticatorDisplayName}} be undefined.
: Client extension output
::