Admittedly, most virtual devices probably usually should show up, but there should still be a way to keep them from showing up in certain circumstances. For instance, I have a line of armors in TBR that, if you have a full set of them installed, will quietly install a virtual device that increases a ship’s shield’s HP by 50%. It’s a slotless device that uses no power, and there really isn’t any need for it to show up on the device listing.
 …That might not be a bad set of criteria for exemptions, actually: If a device is virtual, uses no power, and uses zero slots, don’t show it. It may be better to go for an actual displayOnDockscreen="true|nil" element, though.

megas 13 Dec 2015:

Items should be able to opt-in for no display. It would be a nice feature.