OptionaldecimalsDecimal places in the written unit, 0 to 9. Default 6.
OptionallinearDefault 'metre'. US survey feet write elevations in international feet (LandXML 1.2 has no US-survey-foot elevation unit); both are declared.
OptionalsurfaceSurface@name per product; a blank name keeps the IFC name.
HH:MM:SS, the required LandXML@time.
YYYY-MM-DD, the requiredLandXML@date; the caller owns the clock.