The UNIT keyword sections of the form and media definitions specify the base horizontal and vertical resolution as follows:
the base value specifies the base unit of measurement
the x and y values specify the horizontal and vertical resolution as fractions of the base value (e.g., an x value of 10 and a base value of MM means that the base horizontal resolution is 0.1mm).
The base resolutions thus defined by the UNIT keyword section of the form definition are used as the units of the form definition keyword sections:
SIZE (width and height values)
ALIGNMENT (xoffset and yoffset values)
and of the field definition keyword sections:
POSITION (x and y values)
SIZE (width and height values)
INDEX (xoffset and yoffset values)
The base resolutions thus defined by the UNIT keyword section of the media definition are used as the units of the media definition keyword sections: