diff --git a/website/source/api/index.html.md b/website/source/api/index.html.md
index a446262a1..59ffdecb8 100644
--- a/website/source/api/index.html.md
+++ b/website/source/api/index.html.md
@@ -203,7 +203,8 @@ Individual API's will contain further documentation in the case that more
 specific response codes are returned but all clients should handle the following:
 
 * 200 and 204 as success codes.
-* 4xx codes indicate that if a parameter was modified in the request, it could
-  potentially succeed.
+* 400 indicates a validation failure and if a parameter is modified in the
+  request, it could potentially succeed.
 * 403 marks that the client isn't authenticated for the request.
+* 404 indicates an unknown resource.
 * 5xx means that the client should not expect the request to succeed if retried.