Most people have experience with an employee uniform or dress code policy (mine is “business casual”). There are often very good reasons to have employees look or dress a certain way. It can assist with productivity, promote professionalism and branding, and ensure uniformity. As such, employees’ attire/appearance can be a legitimate concern for employers. However, to the extent that a policy has no rational connection to a business need or unduly infringes on an employee’s self expression, it may be successfully challenged by unions.