Why is there a Single Radio Button Control

[CathyC]

I was writing documentation for the single radio button control and then I couldnt think of a good reason why you would need a single radio button.

The radio button doesnt let you de-select the chosen option until you select another option. But since its a single radio button, there is no other option. So your kind of just forcing or tricking your user to select the option that they cant undo.

I could see a form like the below being a possibility, where the form has many questions and most do have multiple answers, but one has only one option. Either because the other options are not available right now or because it is all that is offered and you know all the users on the form will agree with that option.

Please choose your selection for your rental car:
Vehicle Type:

• Compact Car

Color:

• Blue
• Red
• Silver

Mileage:

• Unlimited
• Limited

But I think you could also use a radio button list control and just set it to only have one option.

Is there a better use case for the Radio Button control that I am missing?