47 CFR § 90.264 - Disaster communications between 2 and 10 MHz.
(a) The use of any particular frequency between 2 and 10 MHz is limited to those frequencies falling within the bands allocated to the fixed and land mobile services as indicated in § 2.106 of the Commission's Rules and Regulations.
(b) Only in the following circumstances will authority be extended to stations to operate on the frequencies between 2 and 10 MHz:
(1) To provide communications circuits in emergency and/or disaster situations, where safety of life and property are concerned;
(2) To provide standby and/or backup communications circuits to regular domestic communications circuits which have been disrupted by disasters and/or emergencies.
(c) The FCC will not accept responsibility for protection of the circuits from harmful interference caused by foreign operations.
(d) In the event that a complaint of harmful interference resulting from operation of these circuits is received from a foreign source, the offending circuit(s) must cease operation on the particular frequency concerned immediately upon notification by the Commission.
(e) In order to accomodate the situations described in paragraphs (c) and (d) of this section, the equipment shall be capable of transmitting and receiving on any frequency within the bands between 2 and 10 MHz and capable of immediate change among the frequencies.
(f) Only 2K80J3E, 100HA1A and those emission types listed in § 90.237(g) are permitted.
(h) Training exercises which require use of these frequencies for more than seven hours a week, cumulative, are not authorized without prior written approval from the Commission.