What does a rectangular sign generally indicate?

A rectangular sign generally indicates regulatory or informational messages. This includes important information that drivers must adhere to, such as speed limits, parking regulations, and other rules that ensure the safety and efficiency of road use. These signs are designed to provide clear and direct communication to drivers about what actions they must take or adhere to while driving.

While other shapes, such as triangles and diamonds, are generally reserved for warnings or caution, the rectangular shape is specifically associated with regulations and information. This is vital for maintaining order on the roads, as non-compliance with these signs can lead to traffic violations or unsafe driving conditions. The other options focus on different categories of signs that serve other specific purposes, but they do not align with the primary function of rectangular signs, which center around regulatory and informational directives.