Although radio buttons can be very useful in DocuSign, optional radio buttons do not function in the way you might think. Even if you make a radio button optional, once you have clicked on one of the options, you cannot undo your selection. Luckily, you can use conditional logic to re-create the function of radio buttons with checkboxes. Below is an example of what this looks like:
*arrows represent conditional rule pointing from trigger to field to appear
This logic works similarly to that of the mutually exclusive text boxes example. Each checkbox triggers a numeric field that gets added to a formula. Each formula has logic corresponding to the other checkbox that shows the checkbox when the formula is 0. As soon as you click on one of the checkboxes, the other one disappears since the formula is now equal to 1. This mimics the function of radio buttons, but once the box is checked it can be unchecked and left blank making it truly optional.