limits*, nominal, plusminus, plusminussym, plusminussym_super
sets the default display for dimension tolerances. groups brought in from other models carry the tolerance display mode that
was in effect when they were created.
limits - displays
dimensions as upper and lower limits.
nominal - displays
dimensions without tolerances.
plusminus - displays
dimensions as a nominal with plus-minus tolerances (the positive and negative values are independent).
plusminussym - displays
dimensions as a nominal with a single value for both the positive and negative tolerances.
plusminussym_super - same
as plusminussym. however, displays the plus-minus
tolerance value at the half-way point of the dimension text and extending upwards.
