Found the answer in 'The Product Guide' of all places
Editing Detected System Exception Categories
Use this task to configure and edit the categories to use to manage exception systems in your network. Exceptions are system that you know are unmanaged (don't have a McAfee Agent on them).
For option definitions, click ? in the interface.
1 Click Menu | Configuration | Server Settings, then from the Settings Categories list, select Detected System Exception Categories and click Edit.
2 Add or subtract exception categories using + and -.
Use the Delete and Change links to modify existing exceptions categories.
3 Specify a name and description for each exception category. For example, you might want to create a category named "Printers-US-NW" to contain all the printers on your network in your company's Northwest regional offices. This way you can keep track of these systems without receiving reports about them being rogue.
4 Click Save.