required

Specifies that the checkbox must be checked before the form can be submitted. Note that, at the time of writing, Safari and Internet Explorer do not support this property.

Note: HTML 5 form validation can be turned off by adding a novalidate attribute to the <form> tag or submit button (this is automatically done by setting validationMethod to 'none' on the standard shipped layouts). In addition, different browsers have differing levels of support for HTML 5 validation and there are many ways for malicious users to bypass client-side validation. So, while client-side validation can improve the user experience, you should never rely on it. Always back it up with server-side validation.

Default value

False

Valid values

True, False, or any valid XPath expression that returns a boolean value.