What kind of structures does the regulations regarding signs primarily refer to?

The regulations regarding signs primarily refer to signs in a broad context, which encompasses various types of signage including digital displays, retail store signage, and billboards. By focusing on signs as a general category, the regulations provide a comprehensive framework that addresses the different aspects of signage design, placement, and usage across diverse settings. This inclusion allows for the consideration of safety, visibility, and aesthetic values in urban planning as well as ensuring that all types of signs adhere to established zoning laws and municipal standards.

In contrast, options like digital displays, retail store signage, and billboards are more specific types of signage. These fall under the umbrella of 'signs' but do not capture the full scope of regulations that apply to the entire category, which is why selecting signs as the answer reflects a more accurate understanding of the regulations' intent and breadth.