If you use SPLITTER before using mkgap, this command should put the version # in same text as MAPNAME

java -ea -Xmx1024M -jar \MKGMAP\mkgmap-r3742\mkgmap-r3742\mkgmap.jar --family-id=111 --family-name="xxx" --product-id=3 --series-name="yyy" --area-name="My_maps" --x-mapset-name=zzz - --latin1 --index --x-split-name-index --bounds=\MKGMAP\bounds.zip --location-autofill=bounds,is_in,nearest --housenumbers --overview-mapname=WW-ov --overview-mapnumber=44444444  --generate-sea=extend-sea-sectors,multipolygon,floodblocker,close-gaps=6000 --make-poi-index --process-destination --process-exits --tdbfile --poi-address --verbose -c template.args master_thin.txt --description="OPENSEAMAP version X" --gmapsupp