I cannot find a CRS description for the USNG to reproject coordinates that look like this: YD307682. YD denotes a square within the grid zone 48Q (Vietnam). There are thousands of those coordinates, and all of them in 48Q-P, 49Q-P grid zones.
I searched for "USNG" and "MGRS" (Military Grid Reference System) on Spatialreference.org. I looked through PROJ documentation. I did many Google searches.
Ideally, I need the description of USNG in Proj string or an EPSG code, stuff that GeoPandas package in Python works with. But if this is not possible, solutions outside of the box are welcome too.
I am a social scientist, cartography is fascinating, but not my field at all.