QRP operation for QRP ARCI purposes is defined as operation with a transmitter power output equal to or less than 10 W PEP output for single-sideband or double-sideband phone (suppressed or full-carrier) and equal to or less than 5 W PEP output for other modes (e.g. CW, FM, AM, digital).
QRP ARCI awards and contests are based on these output levels.