Document authentication exceptions

index.bs

@@ -2745,20 +2745,26 @@ The steps for [=issuing a credential request to an authenticator=] are as follow
 
 #### Authentication API Exceptions
 
-[=[RP]=]'s should prepare to encounter the following {{DOMException|DOMExceptions}} from a call to {{CredentialsContainer/get()|navigator.credentials.get()}}:
+[=[WRPS]=] can encounter the following {{DOMException|DOMExceptions}} from a call to {{CredentialsContainer/get()|navigator.credentials.get()}}:
 
 <dl dfn-type="argument" dfn-for="Authentication API Exceptions">
     :   <dfn>AbortError</dfn>
-    ::  Definition here
-
-    :   <dfn>NotAllowedError</dfn>
-    ::  Definition here
+    ::  The ceremony was cancelled via an {{AbortController}}
+        (see [[#sctn-abortoperation]] and [[#sctn-sample-aborting]] for more information.)
 
     :   <dfn>SecurityError</dfn>
-    ::  Definition here
+    ::  The [=effective domain=] was not a [=valid domain=],
+        or {{PublicKeyCredentialCreationOptions/rp}}.{{PublicKeyCredentialRpEntity/id}} was not a registrable domain suffix of nor was equal to the [=effective domain=].
 
     :   <dfn>UnknownError</dfn>
-    ::  Definition here
+    ::  The [=authenticator=] could not process the supplied options,
+        or encountered an error while generating an [=assertion signature=].
+
+    :   <dfn>NotAllowedError</dfn>
+    ::  A catch-all error covering a wide range of possible reasons,
+        including common ones like the user canceling out of the ceremony.
+        Some of these causes are documented throughout this spec,
+        while others are client-specific.
 </dl>
 
 ### Store an Existing Credential - PublicKeyCredential's `[[Store]](credential, sameOriginWithAncestors)` Method ### {#sctn-storeCredential}
@@ -5919,7 +5925,7 @@ The attributes above are structured within this certificate as such:
   04 12                                  -- OCTET STRING
     04  10                               -- OCTET STRING
       CD 8C 39 5C 26 ED EE DE            -- AAGUID cd8c395c-26ed-eede-653b-00797d03ca3c
-      65 3B 00 79 7D 03 CA 3C 
+      65 3B 00 79 7D 03 CA 3C
 
 30 12                                    -- SEQUENCE
   06 0B 2B 06 01 04 01 82 E5 1C 01 01 05 -- OID 1.3.6.1.4.1.45724.1.1.5