Where Used List

Have you ever used Where-used list button?
Imagine you want to use a standard SAP Function module. You have just joined a company and you were asked to work on a object. You don't have documentation for that function module. In such cases, just click on where-used list button to find out where the function module is used in SAP. Certainly you will find entries which may help you. See below the experience of a developer.
There is this much powerful capability of where-used list which I had not realized until few days back. It all started when I had to use a BAPI namely BAPI_DELIVERYPROCESSING_EXEC to create an item delivery. After going through its documentation and interface, I was totally confused. I searched SDN, Internal SAP documentation, but could not find a single code example. Without any clue, I logged on to one of Sandbox testing servers and was TRYING to use this BAPI successfully, but was unable to do it. Out of my wits, I clicked on where-used list and fortunately there were 4 programs to my rescue.