What is that gesture called?

[Mark A. Mandel]

Jim Landau wrote:
>>>>>
 The whistle [horn] signal for a train approaching a grade crossing is long
long short sustained long ending when the locomotive reaches the crossing.
Sometimes you will see by the tracks near a grade crossing a sign with the
cryptic inscription

   -
   -
   .
   -

This is of course telling the engineer to sound long long short long.
 <<<<<

I tried to remember what that means in International Morse Code, but before
my mind popped up with the answer ("Q") I got a musical hit*: the theme from
what I think of as the Death March, which I remember singing as a child to
the words "Where will we be in a hundred years from now?"

* as in using a search engine

-- Mark
[This text prepared with Dragon NaturallySpeaking.]