These settings concern character conversion including the use of national characters not in the English alphabet, font substitution rules for missing specifications and binary DXF.
Replace Missing Fonts with: If you get a DXF/DWG file containing a style/font specification that does not exist in any of your style/font and font/font dictionaries, you can define a default font here.
Allow national characters in layer, linetype, block names: If the recipient AutoCAD works in the same national environment as your ARCHICAD, you can check this checkbox.
Write binary DXF: This compressed version of DXF takes up about half the space of the text DXF format.
Note: if you really want the data to be compact, it is suggested that you write to DWG format.
Convert Splines into Polylines: Check this box to convert Splines into Polylines in ARCHICAD. ARCHICAD will approximate the AutoCAD Spline using a series of connected straight line segments (that is, a Polyline). This may be useful when in some rare cases, the converted ARCHICAD Spline still looks a bit different from its AutoCAD counterpart.
Replace Missing Renovation Status with: Choose a Renovation status in ARCHICAD for imported elements that do not have an assigned renovation status.