Hi Ann,
I agree that it is sensible to secure the van at the services - even for a couple of minutes, but the point I was trying to make was that these sorts of stipulations tend to appear in the small print and are easily overlooked - until you need to make a claim!
A lot of insurance companies require a wheel clamp to be fitted immediately the van is left for any time at all - sometimes also when the van is in secure storage.
Now my reason for choosing, and recommending, the caravan club is that they are not so strict - a wheelclamp still needs to be fitted once you are on site, but you have a couple of hours to put it on after arriving. Also, they don't require wheelclamps to be fitted in storage - which is fortunate because our storage firm don't allow wheelclamps.
But really I recommended the Caravan Club because, being new to caravanning, there was less for me to think about! Their flexibility regarding security meant that if, in my naive enthusiasm, I forgot to read the small print and made one or two mistakes, and the worst happened, my insurance would probably still be valid!
I know we should all read the small print and make sure we know what we are signing up for but, if you are just starting out, it can be very confusing and things can be overlooked.