https://sambapos.com/wiki/doku.php/custom_reporting_tags
@Tayfun, that ^ WiKi is gone! This is Very Bad! It was a very valuable resource!
I cannot seem to find the same information on Custom Reporting. I looked through the Docs section on sambapos.com, but even the Reporting section is rather bare, and very specific to certain Reports.
You need to bring the WiKi back online, or provide a link to the location where the information was transferred.