Does sign guideline intent trump guideline language?

What is more important and what will stand up in court? If sign guidelines for a development language allows for “individual channel letter and/or graphic logo with acrylic facing” can a city deny a cabinet/box sign that meets all other guidelines simply because the planner believes that it was not the intent of the guidelines to allow box signs when they were adopted? (even thought there is already another box sign in the development) I am having this problem in my city and am not sure my planning director is correct in denying a box sign to an applicant. Any thoughts?