This guide provides a functional and technical specification of smart distribution transformer terminal (as a device) used in distribution network monitoring and operation. It addresses various functions and requirements of the device, such as environmental conditions, power supply, communication and information exchange interfaces, hardware and software design, and application cases. This guide provides an efficient solution for distribution network management with the use of smart distribution transformer terminal, and offers a method to address the evolving challenges, which are brought by the increasing penetration of distributed energy resources and electric vehicles. New IEEE Standard - Active - Draft.