Not really sure about ! marks but here's a neat trick with radio power and CE you can pull legally.
Just include a hardware or hw/sw switch in the device that limits the power from the factory at 10mW. Point out to the test lab that the switch exists and that it is enabled by default, they will write this up in the test report that you can then give to anyone who asks. The test lab may want to confirm this by doing a 'restore manufacture defaults' on the device. Remember, test labs are not the police. Your the customer and so they will test or ignore testing what ever you tell them to.
Once you have passed, self certified and put your nice CE sticker on the box your manual will explain this switch and the consequences of using it. Something along the lines of 'this device is power limited to 10mW as per BS/EN standard so and so'. Then let your users raise hell with their neighbors TV reception with no legal comeback to yourself. If you need to be morally shielded, for the sake of public perception of your product, then make the switch only adjustable by some rudimentary 'hack' that some cleaver teenager can discover and publish online.
A legitimate reason for doing this do exist. Some users, such as mine site operators, SEA FOLK, and so on, are hundreds of km from civilization and have certain exemption's or else just don't care.I know the military generally has a FU approach to trivial things like emissions standards.
[edit]
I missed the obvious reason that @ataradov eluded to. If you want to keep costs down being able to develop and test a single product for a global market requires being able to limit power output for different regions. The only illegal thing here is if you shipped it to EU with the wrong power setting. It's not just output power some ISM bands require a different number of channels for frequency hopping depending on country as well as occupancy time.