Which of the following applies when the FCC rules designate the amateur service as a secondary user on a band?

In frequency allocation, bands are often shared among different radio services. A 'primary' user has priority over a 'secondary' user. According to FCC rules, secondary users are allowed to use the band, but they must always yield to the primary users. Specifically, this means a secondary user must not cause harmful interference to any primary service station. Furthermore, the secondary user must accept any interference caused by the operation of primary service stations. Distractors claiming secondary use is restricted to 'emergencies only' or 'specific hours' are incorrect because secondary use is generally permitted at any time, provided the non-interference rules are strictly followed.