When was last time?

       Periodically within Facebook© (A K A Farcebook, A K A Fakebook) from time to time somebody/some group sticks up a photo with a caption along the lines of
"If you know what this is you're officially OLD."  They really ought to modify it to "˜  ˜  ˜ OLD, or American."
SO - when did YOU last see/use one (dependent upon Gender)

I've been wracking my brains and can't imagine lest time.  I left the Fire Service in '96 but nut sure if I used it at all during my career which I started in '73.