Tic Tac is also a form of sign language, used by bookmakers on British racecourses to indicate fluctuations in betting odds. Practitioners can be seen at courses across the land, wearing white gloves (or sometimes incredibly garish gold rings), standing on wooden crates and waving their hands about frantically as the odds change on particular horses.

Tic Tac comes with its own slang, which is usually derived from the parts of the body being touched to indicate a particular price. Here's a selection -

Levels You Devils - Even money. Self explanatory.
Tips - 11/10. (Indicated with the tips of the fingers).
Wrist - 5/4.
Ear'ole - 6/4.
Shoulder - 7/4.
Bottle - 2/1. (Although I'm not sure why).
Top Of Head - 9/4.
Face - 5/2.
Carpet - 3/1.
Burlington Bertie - 100/30. (Also known as "scruffy and dirty").
Rouf - 4/1. (It's backwards, see?)
Shoulders - 9/2.
Hand - 5/1.
Nevis - 7/1. (Should be Neves, really, but it isn't).
Net - 10/1.
Double Carpet - 33/1.

So, the next time you see John McCrirrick spouting gibberish on the telly, you'll be able to understand him better. Although it's still safer to just switch channels.