The rules provide that certain equipment needs to be certified as meeting FCC regulations before being offered for sale in the US. There are exceptions to that rule. One exception is equipment imported for export. Say you import equipment and sell it down in Miami in the free trade zone. Equipment comes in and goes out of the country. It doesn't need to be certified. Back in the 90's, equipment that worked on CB and Amateur frequencies were offered for sale as equipment for "export" only. The argument was that the radios did not need to be certified because they were only being sold for "export." The term has wrongly carried over to all 10 meter radios, even though the radios, at least the ones made by Ranger, are legal to sell without certification.
Some people, including FCC agents, modify their Amateur equipment to work on CB. A lot more convenient than having two radios in your vehicle. However, transmitting on CB while using equipment which is not certified is a violation of the rules. That's why I only listen to CB when using a 10 meter radio.