A more thorough explanation:

A Clerk of the Pells is a historical officer who worked in the Exchequer. Their job was to record financial transactions on parchment rolls called pells. They would create one roll for money received and another for money spent.

The Clerk of the Pells was also known as the Master of the Pells.

For example, if the King received taxes from his subjects, the Clerk of the Pells would record the amount on the receipt roll. If the King spent money on his army, the Clerk of the Pells would record the amount on the disbursement roll.

These rolls were important because they helped the King keep track of his finances. The Clerk of the Pells played a crucial role in ensuring that the King's money was properly accounted for.