Yes, there is a "techno name" for that "C" channel rail extrusion. It's called
Keder rail, and is commonly used with conventional "Rope and Pole" awnings and "Bag" awnings. I didn't like the factory installed Fiamma awning that came with my trailer because it didn't seal up tightly to the side of the trailer, and water would come cascading down the side of the trailer whenever it rained (hey, I live in the Pacific Northwet (sic), so I removed it, and now I have a section of that Keder rail on the side of my trailer for a R&P awning.
Now whenever I slide my R&P awning into it, there is no more water running down. I also have a pop-up Clam screen room shelter as well if I'm going to be somewhere for several days, but if I'm only setting up for a day or two, I'll just use the slide-in awning.
I also had an extra piece of the rail left over after my awning project, so I used it to make a small slide-in quick set-up table for the side of the trailer. It's basically an aluminum "full sheet" baking pan with some odds and ends of scrap aluminum strap for an angled removable support leg. All aluminum, no rust and
light weight. It's also handy to the outside 120 volt outlet too.
http://nepcosignsupply.com/store/pc/...dCategory=1835