Please remember the CAMS requirement

all vehicles must display an upper case “N” directly followed by a lower case “a”, “b” or “c” (as appropriate) being black or white contrasting in colour to that of the bodywork, 100mm and 80mm in height respectively in typeset Helvetica Bold Condensed immediately following the vehicle’s racing number at the bottom right hand corner, no further than 100mm from the border of the background.

This is on Page 6 in the CAMS document – VEHICLE ELIGIBILITY – HISTORIC TOURING CARS Last updated: 1/1/2019