options / README.rst

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File README.rst

 superclass's options should not effect the subclass's options.
 With ``add()``, they remain linked in the same way as instances and classes are.
+Some options do not make sense as permanent values--they are needed only as
+transient settings in the context of individual calls. The special null value
+``Transient`` can be assigned as an option value to signal this.
 Flat Arguments