You can create a report of unused variables. In version 7, which is what I have on the machine I'm using for internet browsing, you click on the "Variables" tab and one of the choices is "Reports" which bring up a window with a drop-down list of options, ine of which is "Unused variables". The look and feel of PME changed around version 9, so I'm not sure if that's exactly how to get to the reports in version 9.8