This variable allows you to adjust the size of the wide font measurement (applies to variable-pitch fonts only). The wide font measure is normally used when the runtime is measuring small or upper-case entry fields. The value of FONT_WIDE_SIZE_ADJUST is added directly to the computed wide font size.
After applying the adjustment, the runtime checks and ensures that the computed wide font measure is not smaller than the (adjusted) standard font measure or larger than the widest character in the font. If your upper-case fields are not quite as wide as you prefer, try setting this variable to a small value (typically 1 or 2).
Generally, it is recommended that FONT_WIDE_SIZE_ADJUST (and FONT_SIZE_ADJUST) be left at its default value of 0. You can also use negative values, but there is rarely a need to do so.