Default Text Style:

Assign the default Font to use when an associated  font cannot not be determined or located.

TrueType Font Options:

Select TrueType Font Quality - the higher the number the more smoother the text, however file sizes will be much larger.  In most cases the default 5000 will work fine.

Use Polygon/Raster Fill allows TrueType fonts to be filled in using polygon/raster fill - this is the preferred method.

Text Line Width:

Use Same Line Width for All: Determine a standard line width to be used for all DXF text.

Use Ratio: The text line width will be determined by a ratio of the text height divided by your supplied value.