47 CFR 95.531: Permissible FRS uses.

FRS units are primarily used for short-distance two-way voice communications between individuals.

(a) Digital data. In addition to voice conversations, FRS units may transmit digital data containing location information, or requesting location information from one or more other FRS or GMRS units, or containing a brief text message to another specific GMRS or FRS unit. Digital data transmissions may be initiated by a manual action of the operator or on an automatic or periodic basis, and a FRS unit receiving an interrogation request may automatically respond with its location. See also § 95.587(c).

(b) One-way communications. FRS units may be used for one-way communications that are emergency messages, traveler assistance communications, voice pages or brief equipment tests.

(c) GMRS stations. FRS units normally communicate with other FRS units, but may also be used to communicate with General Mobile Radio Service (GMRS) stations.