Reflective stickers often in the form of tape are a crucial safety feature for trailers, significantly increasing their visibility to other drivers, especially in low-light conditions or at night. Beyond improving safety, the use of reflective markings on many trailers is mandated by government regulations in various regions, including the United States and Europe.

In the United States, the Department of Transportation (DOT) through the Federal Motor Carrier Safety Administration (FMCSA) and the National Highway Traffic Safety Administration (NHTSA) has specific requirements for reflective tape on commercial trailers. Generally, trailers with a gross vehicle weight rating of over 10,000 pounds and a width of 80 inches or more are required to have conspicuity treatment.

Key requirements under US DOT regulations (often referred to as DOT C2) include:

Color: Alternating red and white strips along the sides and lower rear of the trailer. White (or silver) strips are required for the upper rear corners in an inverted "L" shape.
Width: The tape must be 2 inches wide.
Sides: Applied horizontally as close as practicable to the bottom of the trailer, covering at least 50% of the length, evenly spaced.
Lower Rear: Applied horizontally across the full width of the trailer, as close as practicable to the bottom.
Upper Rear: Two 12-inch white strips in an inverted "L" shape near the top outer corners.
Certification: The tape must be certified to meet the requirements and will typically have a "DOT C2" marking.
European regulations, such as ECE 104, also require reflective markings on large goods vehicles and trailers, with specifications for color (white, yellow, or red depending on the location on the vehicle), coverage (outlining the contours of the vehicle), and reflectivity performance (Class C being the highest for contour marking).