I ran a caravan storage site on 2.8 acres and had 220 vans in storage for 10 years. Problems despite security fencing were theft. Some of this was organised theft from my site and two others. The vans were taken to a Gypsy site in Carlisle where they were collected by a legitimate haulage company and taken to Stranraer for export to Ireland. The ferry company accepted then as green caravan or blue & white caravan and the person booking then in accepted a cross as a signature.
A further spate that put me out of business was a local Garage. They drove a transporter through the fence and loaded a van with wheel clamps, steady locks, and alarm. The van next to this one was the same model a year older with no security. They were definitely sealing to order. They were eventually caught the day I closed. They were found in the compound loading a van onto a transporter and they had five other vans on cars ready to go.
They were obviously watching me as I lived on site but from time to time had to pop out. It was always at these times that I was done.
I have been the exemption certificate for a club that has all of the exemptions. There are actually 15 clubs now that can issue CL type exemptions to site owners.
Information here:
http://www.naturalengland.org.uk/Images/combined-guide_tcm6-9572.pdf
The 28 day rule applies to one caravan for no more than 2 nights on unlicensed land. It has been quoted even by DEFRA in other circumstances but if you read the act it only applies to that one section. The 28 days use of a CL or Holiday site is an agreement between DEFRA (Natural England) and the Big clubs and The Association of Caravan and Camping Exempted Organisations which represents about 50% of exempted clubs.
As has been stated before a properly constituted club can get exemptions without going through ACCEO. I have done it for my own club and a National Organisation. I got both organisations para 4, 5 and 6 plus camping.
If you go on line and look for "Caravan Sites Model Standards" you will see the requirements that are required for a licenced caravan site.
An example here:
http://www.suffolkcoastal.gov.uk/NR...9DB4017B/0/EMASMODELSTANDARDSTOURINGSITES.pdf
There are also different standards for Residential sites.