IMHO, we need to precede signals #30 RTK/H or #45(FM) with PF if 5 or 15 yd enforcement. There are several seldom used signals that I feel helps to identfy as a personal foul, They are:
#24 Illegal helment contact/targeting
#25 Blindside block
#34 Roughing the passer
#39 Clipping
#40 Blocking below the waist
#41 Chop block
#46 Tripping
Several years ago we had a chop block call. I gave only signal #41. The PA announced: "ERR...I guess 'offsides' is a 15 yard penalty now

"
My enjoyment in waving my arms may have came from my daze of youth when passenger trains rumbled thru Maine. My buddies and I would wave to the passengers. Some would wave back, some would only wave one finger

. Passenger trains stopped in mid-60's. We then found more mischievous things to do.

NOTE: Not all 15 yd fouls involve dangerous contact, such as IP, but needed to be treated as such to allow for previous spot enforcement.