Specify a font name to substitute a font name specified in the descriptor.
This setting also applies to the overlay.
"Old font name" "New font name"
MAPFONT "Courier New" "Arial"
MAPFONT "Century" "SimSun"
Font name specified in the descriptor is used.
When the specified font is not found, the default of the font actually used is as follows by the operation locale.
China: SimSun
English: Courier New
Portugal: Courier New
