Merge branch 'tc-clientfeatmethod' into tc-remove-isPPAA

# Conflicts:
#	index.bs

index.bs

@@ -3944,6 +3944,33 @@ Note: The {{UserVerificationRequirement}} enumeration is deliberately not refere
         interest of minimizing disruption to the user interaction flow).
 </div>
 
+### Client Capabilities Set (dictionary <dfn dictionary>ClientCapabilities</dfn>) ### {#dictionary-client-capabilities}
+
+<xmp class="idl">
+    dictionary ClientCapabilities {
+        boolean userVerifyingPlatformAuthenticator;
+        boolean hybridTransport;
+        boolean passkeyPlatformAuthenticator;
+        boolean conditionalMediation;
+    };
+</xmp>
+
+This dictionary defines a limited set of client capabilities which a [=[WRP]=] may evaluate to offer certain workflows and experiences to users.
+
+<div dfn-type="dict-member" dfn-for="ClientCapabilities">
+    :   <dfn>userVerifyingPlatformAuthenticator</dfn>
+    ::  The [=WebAuthn Client=] supports usage of a [=user-verifying platform authenticator=].
+
+    :   <dfn>hybridTransport</dfn>
+    ::  The [=WebAuthn Client=] supports usage of the {{AuthenticatorTransport/hybrid}} transport.
+
+    :   <dfn>passkeyPlatformAuthenticator</dfn>
+    ::  The [=WebAuthn Client=] supports usage of a [=passkey platform authenticator=], locally and/or via {{AuthenticatorTransport/hybrid}} transport.
+
+    :   <dfn>conditionalMediation</dfn>
+    ::  The [=WebAuthn Client=] is capable of {{CredentialMediationRequirement/conditional}} mediation.
+
+</div>
 
 ## Permissions Policy integration ## {#sctn-permissions-policy}