-When \av@_scanner\ is correcly set, you can use the \malware\ condition in the
-DATA ACL. The condition takes a right-hand argument that is expanded before
+When \av@_scanner\ is correctly set, you can use the \malware\ condition in the
+DATA ACL.
+
+The \malware\ condition caches its results, so when you use it multiple times
+for the same message, the actual scanning process is only carried out once.
+
+\av@_scanner\ is expanded each time \malware\ is called. This makes
+it possible to use different scanners. See further below for an example.
+However, using expandable items in \av@_scanner\ disables the result caching
+of the \malware\ condition.
+
+The condition takes a right-hand argument that is expanded before