The QSA code was mandated by the Madrid Convention (Appendix 10, General Regulations) sometime prior to 1936, and specified the following reporting format, as found in the 1936 edition of the ARRL's The Radio Amateur's Handbook[3] and Radiotelegraph & Radiotelephone Codes, Prowords, and Abbreviations.
[1] The 1945 U.S. Army Radio Operator's Manual, FM 24-6 defines the radiotelegraph signal report format as follows:[6] FM 24-6 further states, "Readability and signal strength reports indicate the desired method of transmission and should be used in that sense.
The report example given below uses military call signs and the obsolete Q Code of QJS for readability instead of the current QRK:
The 1943–1945 Combined Communications Board Publications, including CCBP 3-2: Combined Radiotelephone (R/T) Procedure,[7] describe a slightly newer radiotelephony version of the radiotelegraph procedure described in the U.S. Army Radio Operator's Manual, FM 24-6:(a) A station is understood to have good readability unless otherwise notified.
will be a short concise report of actual reception such as "Weak but readable," "Strong but distorted," "Loud and clear," "Strength Four," etc.At least in CCBP 3–2, no additional detail is given about what the range of the numeric scale is, or the complete list of strength and readability code words are.