It is on the current site but it is well hidden with no link that I could see to it from the homepage (I did a google site search to find this) and I can only presume it is the info for this years fest:-
It states the following:-
You may bring the following to the festival
12 cans beer / lager / cider / pre-mixed drinks OR 2 bottles of wine (decanted into plastic bottles) per person OR a combination of the two i.e. 6 cans and 1 bottle.
Strictly no spirits or hard liquor.
You may only bring your allowance of alcohol in on first entry. You cannot leave site and return with more. Searches will be undertaken upon entry. If you leave the site, you may be searched again upon re-admittance.
Any alcohol above this allocation will be confiscated.
This alcohol may only be consumed in the campsite.