A URL that resolves to additional supporting information or guidance related to the question. If there's more than one repetition of this extension, all a UI can do to help the user differentiate which to click on is displaying the URI (e.g. as a flyover). If displaying the URI might not be appropriate or helpful, it may be more useful to use a nested 'display' item of type 'helpText' which can then specify multiple hyperlinks with appropriate labels and/or surrounding guidance text. This extension has been deprecated in favor of questionnaire-supportHyperlink, which allows display text to accompany each support link. This extension only conveyed the URI, making it unclear to users what each link referred to.