Hi Joseph - according to the Fresno Citywide Development Code - RMX is "Regional Mixed Use"
RMX Regional Mixed-Use. The RMX district is intended to support regional retail and mixed-use development in large-scale activity centers outside of Downtown, as identified by the General Plan. It accommodates urban-scale mixed-use development that serve residents and businesses of the region at large. Medium-scale retail, housing, office, civic and entertainment uses, and shopping malls with large format or “big-box” retail are allowed, as are supporting uses such as gas stations, hotels, and residential in mixed-use or single-use buildings. Development and design standards will create a pedestrian orientation within centers and along major corridors, with parking located on the side or rear of, or within, major structures.
you can get more detail about it here:
https://www.fresno.gov/darm/wp-content/uploads/sites/10/2016/11/FresnoCitywideDevelopmentCode.pdf
best of luck and let me know if I can help you with anything in Fresno area