d. To avoid interfering with other traffic, an operator shall listen in to make certain that a circuit is clear before making an trans~ missions thereon. 10. Establishing Communications Before conducting regular traffic over radiotelephone circuits, it may be necessary to make contact with the other station (s) involved to acsertain that communications is possible. 11. Signe) Strength and Readability a. A station is understood to have good signal. strength and readability unless otherwise notified. Strength of signals and rendabil- ity will not be exchanged unless one station cannot clearly hoar another station. b. A station that wishes to inform another of his signal strength and readability will do so by means of a short and concise report of actual reception, such as "Weak, but readable", "Strong, but distorted", "Loud and clear", etc. Reports such as "Five by five", "Four by four", etc., will not be used to indicate strength and quality of reception. A station desir- ing to know how his transmission is being received will transmit "How do you hear me?", "What is my readability?", “Report my signals", etc. H2-5