Cecil Moore wrote:

...
My Webster's unabridged dictionary gives the following
examples of the correct way to pluralize numbers.

"figure 8's", "the 1890's", "the 20's"

73 is a number that stands for "Best Regards"

73's would be "Lots of Best Regards".

A friend of mine is a dispatcher for police/fire/ambulance/etc., in my
area. Her 10 code often requires her to use the "10-73" from this ten
code--which is a "smoke report."

So, thanks for clarifying this for me. I simply took the 73's on many
of the posts sigs as a sign they were "blowing smoke" (actually, "Lots
of smoke!" :-) ), and giving me fair warning! straight-face

Regards,
JS