All ads must be approved by Blip and by the sign owners of the boards you select. Each sign owner has different criteria for approval and will approve ads on a one-to-one basis. Unfortunately, not all sign owners disclose their approval guidelines.
The best way to see if your ads will be approved is to test it out. We recommend you set up your campaign, submit your artwork, and wait for the approval email (you will not be charged until your ads are approved and start running). If your ad is rejected for content reasons or because it is a personal ad, try selecting a different billboard.