---- dataentry configoptions ----
type             : constant
name             : CHECK_REFERRER
purpose          : Verify that the referring web page is allowed
allowed          : true false 0 1
default          : 1
status_s         : 
category         : security
----

This is a small check on validity of a request and will not protect completely. But it won't hurt either.

In order to allow referrers you know, you can use [[allowed_referrers]]

If you continuously get "Access denied" when using phpList, you will want to switch this off.