I do not disagree that "Unsafe Entries" is an ambiguous term. Personally, I knew what Comodo meant, but I did feel that other users might not.
However, I would like to talk about the possible damage that may be caused by removing these entries & how you can quickly get a feel for what they are (ie. if you should delete them of not).
The risk of any catastrophic damage (ie. OS crashes, unable to boot, etc..) from occurring by deleting "Unsafe Entries" is, in my opinion, minimal. Comodo have done their best to avoid these device related entries. But, it cannot be ruled out. That's because how the registry is used is not defined by Comodo (or by MS for that matter) & some vendors use the registry in very devious & tricky ways (usually on purpose).. Protection software (DRM) for games tend to do this.
To address how to quickly investigate these entries & what sort of damage you are more likely to cause, let's look at an Unsafe Entry that CRC gave me..
On face value, I have no idea what that means, other than it is something to do with an Uninstall. I highlight the entry, right click & select Go to Registry...
. This opens RegEdit & finds the corresponding entry that CRC has spotted in the Registry. No real technical knowledge is needed here, since I can see in clear language that this is the Uninstall entry for Activision's "Call of Duty 4 - Modern Warfare". So, if I allowed CRC to delete it.. I probably wouldn't be able to uninstall COD4 via the usual method. This is minor damage.
The majority of Unsafe Entries can be safely deleted because they are invalid. But, if you see anything to do with game protection software (DRM: SecuROM, Tages, etc..) leave it well alone, even if you've uninstalled the game or it looks completely invalid.
I hope that helps.
edit: DRM Games [Wikipedia]