We have an internal AngularJS application that collections information about events and participants.
Some fields are required and some are optional. Unfortunately there are a few fields (like phone number) that are optional but required, the powers that be have requested that add something that make the user click an "Unknown" button. This is so the user has to say it's not known (or does't exist) instead of just accidentally leaving it blank.
Is there a better way of accomplishing this that I can present as an alternative. To me it seems like having to put that button or check the checkbox ruins the flow of the form (which can contain a dozen or more fields, with a few being of this optional/required format)