I am not sure if this is a global thing, but the practice of writing stuff down on currency notes is rather widespread in India. If you are reading this post in India, check your wallet right now. I am sure that half the notes would have something scribbled on them.
The most common thing is the count of notes. Usually, when people are making stacks of 100 notes, they mark the count on the topmost note. In my wallet right now, I have 7, 49, 84 and 100 marked on notes. Another common thing is names and/or phone numbers.
But it is a rare note that is blessed by a poetic verse or a shopping list. I got this one as change a couple of days ago:
I didn’t even know there was such a deodorant on the market!
I have edited out the mobile number scribbled on the note. Also check out the serial number – a pretty good hand to hold while playing Liar’s Poker.
Now, what do you have in your wallet right now?