This paper describes 2D specifications of the IEEE Map Data Representation (MDR) standard and introduces the ongoing efforts for developing 3D MDR specifications. The 2D MDR standard is well-suited for current robot applications utilizing 2D maps, which may include autonomous road navigation, robotic logistic systems, defense and rescue robots, and service robots for personal or domestic applications. In addition to their original purpose as a common format for representing the spatial environment for robot navigation, the developed MDR standards are expected to contribute to promote development of good experimental methodologies for mobile robotics as a valuable tool for facilitating comparison and evaluation of maps obtained from different systems or methodologies.