diff --git a/src/modules/sanity/README b/src/modules/sanity/README
index 90ea8789c11..4a7fe1ec4c8 100644
--- a/src/modules/sanity/README
+++ b/src/modules/sanity/README
@@ -92,6 +92,11 @@ Chapter 1. Admin Guide
      * digest credentials (2048) - Check all instances of digest
        credentials in a message. The test checks whether there are all
        required digest parameters and that they have meaningful values.
+       NOTE: the message will be considered invalid if the authorization
+       scheme differs from "digest",
+     * authorization header (8192) - checks if the Authorization is valid
+       if the scheme is "digest" (see "digest credentials" above), always
+       returns success for other schemes.
 
 2. Dependencies