Changing usage type in datadict

In order to be abel to fill the fiels subcatagory and area, on templates, it's necessary to change the usage type on subcatagory from system to application in datadict for the incidents table.

I did that, and apparently is working perfect, but my supplier warns me that it mayby could cause problems.

So now my question for you.. have you ever made a change like that, and experiencende any problems after ??

Thanks :-)