49 CFR 220.45 : Transportation (§ 1.1 To Parts 1581-1699) — (§ 200.1 To Parts 273-299) — Other Regulations Relating To Transportation (Continued) (§ 200.1 To Parts 273-299) — Federal Railroad Administration, Department Of Transportation (§ 200.1 To Parts 273-299) — Railroad Communications (§ 220.1 To Appendix C To Part 220) — Radio And Wireless Communication Procedures (§ 220.21 To § 220.61) — Radio communication shall be complete.

4 Aug 2016

Any radio communication which is not fully understood or completed in accordance with the requirements of this part and the operating rules of the railroad, shall not be acted upon and shall be treated as though not sent.

49 CFR 220.45