The archetypical design of jeans includes five pockets, a front fly, five belt loops, and a yoke at the back. Of the five pockets, two are stitched-on at the back, two are curved inset pockets a the front, while the last pocket is a small patch pocket that’s half-tucked into the left front pocket.
The small patch pocket on the front is most commonly known as the ‘coin pocket,’ but some call it the watch pocket or the match pocket.
It’s a common misbelieve that the coin pocket is the fifth pocket, meaning the one to have been added last. It was, however, the left back pocket that was added last (in 1901 to be precise, according to Levi’s).