What markings are specifically outlined in yellow?

The markings that are specifically outlined in yellow are the runway intersection hold short markings. These markings are critical for ensuring safe aircraft operation on the runway by indicating to pilots where they must stop if they are about to enter an active runway. This is particularly important at points where taxiways intersect with runways, as it helps to prevent runway incursions and maintain safety in operational areas.

Other types of runway markings, like centerline markings and aiming point markings, are not outlined in yellow and serve different purposes within the runway operational framework. Centerline markings, for instance, assist pilots in maintaining their alignment during takeoff and landing, while aiming point markings are designed to guide pilots to the appropriate touchdown area on the runway. However, neither serves the specific safety function of hold short markings, which are crucial in areas where potential conflicts with other aircraft could occur.