When creating your custom property tabs, every attribute will give you an option for configurations:

You can choose to have your attribute show up in the custom tab (file specific) or the configuration specific tab.  Seems simple enough.  However, in some PDM systems, there is some data that you will want to show up in BOTH the custom and configuration specific tabs in order to map all of your variables correctly.  Enterprise PDM, for instance, keeps track of custom tab and configuration tab data on seperate cards.  Nobody wants to write data in twice, is there a way to write the information into BOTH custom and configuration tabs within the property tab?

If not, then perhaps this would be a nice topic for improvement in the next service pack or in the 2012 release of SolidWorks.