how to include none option to a radio button field which is marked required

[Deepa Tantry]

Basically I need the custom field to be a required field with options yes/no. By default currently some value is selected for this field. The value should not be preselected. It should either be blank, or a none option should come up which acts as default. If the user proceeds with none, it should error saying the field is required and either yes/no should be selected.
Any solution for this requirement is highly appreciated!
Thanks

[Deepa Tantry]

Thanks for all your responses!!!

When i create the radio button with yes/no options, by default i see "None" Option enabled and selected.
When i make the field required, the none option vanishes and the "No" Option is selected by Default. I do not want the field to preselect the value to both Yes or No.

Say, the User does not notice this field in the screen but he actually had to select "Yes" as an option. However, the field is defaulted to option "No". If the user proceeds, we would not know if the selected option was given by the user or it was because of the default value.

Please let me know if there is a way to remove the preselection from the Radio button.

Appreciate your responses.
Thanks for your help.

[Joe Pitt]

You need to remove the default value from the configuration. 

[Joe Pitt]

If you just want to verify they saw the field and picked something you need to have an option of N/A or something like that they can select indicating none of the others apply, but I picked something.

[Nic Brough -Adaptavist-]

This makes no sense.

If a field is mandatory, you are saying "you must give me a value for the field".  "none" is not a valid response.  So you really do not want that to appear as an option.

Leaving a field blank and forcing a selection is fine, and that's the behaviour JIRA goes with if you set the field mandatory but do not specify a default value for it.

[Alex Christensen]

It sounds like this field is configured to have a default value. If you create a radio button custom field, don't assign a default value, and make the field required, none of the values should be selected when creating an issue.