[bossref]

Guys
I had this discussion years ago and won a bet too.
I had to write to NASO for proof(Feb 1986).
I still have the letter!
Their response was that it was a "common practice" to
show the travelling signal (so as to let everyone know
that a violation had occurred).
However, they did note that the 1985-86 mechanics manual
says to NOT use the travelling signal.
Stop the clock (Open Palm)and point to the spot
while verbalizing the color of team entitled to the ball
and point the direction.
I also teach to move your hand side to side (3 feet)
very similar to a 3 seconds violation motion, just
after you point to the spot.
Big problem is coaches, television commentators, and too
many refs think that it is travelling!
You can only travel if you have a PIVOT FOOT!
Since a thrower-in may jump or even move backwards,
we all know that a pivot foot does not exist.