Year 66 (LXVI) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Telesinus and Paullinus (or, less frequently, year 819 Ab urbe condita). The denomination 66 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Continuous redial, busy number redial, or repeat dial, is a vertical service code (calling feature) that allows callers to automatically redial a busy telephone number until a connection is made. It is activated by dialing a combination of special characters and numbers after hanging up following a call to a busy line. It will run for a set period of time (such as 30 minutes) and can be deactivated by entering either the same set of numbers or a different set. The North American Numbering Plan assigned *66 to activate continuous redial and *86 to deactivate it.

Thailand's telephone numbering plan in Thailand is managed by the National Broadcasting and Telecommunications Commission (NBTC) in accordance with International Telecommunications Union's (ITU) recommendation E.164.