The Modified Transverse Mercator (MTM) coordinate system is a metric grid-based method of specifying locations, similar to the Universal Transverse Mercator coordinate system. MTM uses a Transverse Mercator projection with zones spaced 3° of longitude apart.
The coordinate system is used in Eastern Canada.
It is used also in Nepal.
References
Modified Transverse Mercator coordinate system Wikipedia(Text) CC BY-SA