For AutoCAD fonts the font style is obtained from the shx/shp font file and a shape file may have many styles.
This line maps style htx1 in font file
o8116901.shx to the MicroStation font 168 using an X scaling factor of 1.09 and no oblique characters. The value of 1.09 for this particular mapping was obtained by experiment and compensates for the arbitrary character spacing output by ISODRAFT.