On a sd card (G:\) you can write:
1) In fodler G:\Garmin\JCV\ the JCV file
2) In folder G:\Garmin\ASR\ all the ASR files from here, for every new version of CNEUNT
In device, you will keep the folder Device:\.System\ASR\ which has the files of the languages that are enabled (those files are updated with WebUpdater).
3) In folder G:\Garmin\SID\ all the SID files from here, for every new version of CNEUNT
4) In folder G:\Garmin\ you can write the map file for CNEUNT, using the name gmapprom.IMG
or
In folder G:\MAP\ you can write the map file for CNEUNT, using any name you like (but always with the extension .IMG).
Also, you can write a Nautical chart-map (G2 or G2 Vision ) in folder G:\Garmin\ with the name gmapsupp.IMG (for HomePort to read it)