What does a lollipop lady, or man, always have in their pocket?

As there is nobody else out there in the WHOLE WORLD who knows this I may just have to tell you. Anyone who has seen a lollipop person will be familiar with the logo on the stick "STOP CHILDREN CROSSING" with a black band across. The black band is actually a board on which the numbers of any cars which do not stop when requested to, or which recklessly endanger the life of children crossing the road, may be written, and to that end a lollipop person should always have a piece of chalk in their pocket. You may all rest easy tonight knowing that. :)