Mal's comments aside, "QRSS" arose as a way to differentiate CW described in words per minute from the slower variety best described in seconds per dot. "QRSS3" unambigously meant CW sent at 3 second
Are we to understand then that your report meant : M0BMU was heard sending CW using the morse code at 3 words per minute, DL2HRE using CW with frequency shift keying but the code and speed used were