A photoplotter usually needs to know which apertures are
assigned to the codes used in the output file. These assignments
are defined in an Aperture Wheel File.
Examples
D010 annulus 0.004 x 0.000
D010 round 0.004
D040 square 0.004
D054 thermal 0.090 x 0.060
D100 rectangle 0.060 x 0.075
D104 oval 0.030 x 0.090
D110 draw 0.004