What's the noun for chitty? Here's the word you're looking for.
chit
(US and Britain dated) A small sheet or scrap of paper with a hand-written note as a reminder or personal message.
A voucher or token coin used in payrolls under the truck system; scrip.
(pharmacology) A small sheet of paper on which is written a prescription to be filled; a scrip.
(gaming) A smaller cardboard counter generally used not to directly represent something but for another, more transient, purpose such as tracking or randomization.
(India, China) A signed voucher or memorandum of a small debt, as for food and drinks at a club.
(US, slang) A debt or favor owed in return for a prior loan or favor granted, especially a political favor.