To specify a base name to use in default format names for ditamap and bookmap elements:
[ElementOptions] ; BaseMapFormat = base format name to use for ditamap elements BaseMapFormat = Map
DITA2Go appends a two-digit document level number to the base format name for each map level, such as Map02. The default base name is Map.
DITA2Go treats the value of BaseMapFormat as the default format name for map elements for which the [BlockFormatMaps] section does not contain a contextual mapping. The main use of BaseMapFormat is to help identify such omissions, so you can map those elements to new or existing formats. An exhaustive [BlockFormatMaps] section would be very large, and pretty unmanageable.