Just to add to this, and hold my hands up, as the post above might come as a bit of surprise...
This clarification of the rules comes as a result of what I thought was a pretty safe post on daft thread elsewhere on oOple.
After my post I was contacted directly by the BRCA offroad section (and that doesn't mean Martin!) and told that my understanding of the rule book was incorrect.
So...since my (bad
) understanding of the rules has been reinforced by my experience of racing in regionals over the last few years, it would appear that the regions I, and a lot of others, have raced in have not been following the BRCA rule book properly previously.
Although the racing has always still felt fair without this, and been great fun previously, I'm looking forward to having the racing and organisation raised to the regional and national standard as it should be...Voltmeter, EB lists, scales and box at the ready then!