Some SAPscript printer drivers (for example, the PCL-5 driver HPL2) generate a printer command for font selection from the definition of a printer font. Each SAPscript font family (such as COURIER, HELVE, TIMES) has an attribute "proportional" or "nonproportional", which is specified in SE73 in the list of the font families when the font family is created, but for certain fonts (such as Asian fonts for Japanese, Chinese, etc.) this attributes does not correspond to the "proportional font" attribute expected by the printer in the font command. For particular printer drivers, this field allows to overrule the "proportional font" attribute determined in the list of font families in SE73 for a printer font.
Example: The font JPMINCHO (Japanese font in SAPscript) is flagged as "nonproportional" in the list of font families in SE73, but PCL-5 printers handle this font as proportional font and require the attribute "proportional font" in the corresponding PCL-5 printer command.