A plain-language radio check is the means of requesting and giving a signal strength and readability report for radiotelephony (voice) communications, and is the direct equivalent to the QSA and QRK code used to give the same report in radiotelegraph (Morse code) communications.
SINPEMFO code is the voice signal reporting format developed by the ITU in 1959, but sees little use outside of shortwave listeners.
Section 611 of ACP 125(F) details how to conduct radio checks using plain language.
The prowords listed below are for use when initiating and answering queries concerning signal strength and readability.
For example: The omission of comment on signal strength and readability, by responding only with the proword ROGER, is understood to mean that reception is LOUD AND CLEAR.