I was just reminded of a bad practice by W1AW. That is the failure to use a separation between numbers and fractions. For instance W1AW sends 7-1/2 WPM as 71/2 WPM. The use of a dash to separate a number from a fraction is made clear in, for instance, the 1968 edition of the General Post Office handbook for radio operators on p.154 and in most other books on telegraph operating. I think it is well established and goes back to wire line practice although I have not looked it up. It makes good sense to use it. The ARRL seems to go its own way but people are supposed to learn good practice from their transmissions so this is a fairly serious error.