A pigeon-hole messagebox (commonly referred to as a pigeon-hole or pidge, a cubbyhole (often shortened to "cubby") or simply as a mailbox in some academic or office settings) is an internal mail system commonly used for communication in organisations, workplaces and educational institutes in the United Kingdom and other countries. Documents and messages are placed in a person's pigeon-hole for them to collect; they can reply by putting a response inside the sender's pigeon-hole.