Porch awning

We had a similar shaped awning at one time and the rear legs were pegged to trap a pad that formed the rear of the sides to the caravan. I suspect that to be pretty standard but others may have better info

Porch awnings don’t usually fix to the side of the caravan but rely on tension of the upright to keep it in place. Hence, you can experience some flapping or tapping noises when it’s windy. 

Edit: Cross posted with you, Easy. 

I found that the pad trapped by the rear leg kept it fairly well positioned

Many Thanks  for the replies  , I wasn't sure if I needed extra poles  or pads to secure , and guess I wont know fully till erected and windy

I would check to see that the main tenting incorporates rear pads. Looking at the website it does not appear to have and relies on pegging the rear of the awning under the caravan

http://royal-leisure.co.uk/wp-content/uploads/302628/302628-Oxhill-390-Awning-Instructions-Hi-Res.pdf

http://royal-leisure.co.uk/product/royal-oxhill-390-awning/

I’d expect it to have everything you need, Keith, with the possible exception of decent pegs. 

Thanks for the links Easy T

think about an air version of that design. It's all down to personal choice but I found that bending those poles (the black curved parts) does take some effort and then you have to secure them on the ground and it looks as you'll have to do that four times. An air awning will simply expand to that shape. Either with a few strokes of a pump or you can get an electric inflator. It does cut the time needed significantly at both ends of your stay. You'll still have to peg it of course.

We had to but the upright poles as an extra.

Keith As you have the rear poles a simple fix to obtain a better ,flap free, fit is to wrap the rear poles with some foam water pipe lagging.