SimonMorgan
June 2020 edited June 2020

Hi Joe. I don’t think you use the word “right” at all (or the word “ahead” which implies: on this road). The arrow is all you need to show the restriction is on a side road.
See the DfT working drawings. This is clearest on p 2 of P818.3, which is now easiest to find on the National Archives website here.