What is generally used on stanchions but can also be applied in many other places where a round core is to be covered?

The correct answer is cross pointing. It refers to the method of covering and securing loose ends on stanchions or similar structures, which helps to provide protection and maintain an aesthetically pleasing finish. Cross pointing is often used because it forms a strong bond around the core, creating a durable covering that can withstand environmental stresses.

While railing is related to stanchions, as it is often what stanchions support, it does not serve the purpose of covering a core. Similarly, trim typically refers to the decorative finish around openings or edges and is not specifically designed for covering round cores. Wiring, while an important aspect of securing and fastening on boats, does not apply in the same manner as cross pointing for this specific purpose. Thus, cross pointing stands out as the appropriate choice for this application.