Is there someone to have an either or requirement? To clarify, I'd like to get either a clients email address or phone number to contact them back without having to require both.
If you put your two questions into a section but don't make either of them to "Require a value", then set the validation on the section to be "At least one of the questions must be answered", then I think this will do what you want. You might want to indicate via some text that the user can supply one OR the other OR both.