Your clothing will be scrutinised and the clothing-scruts will sign the group label that should be on the right hand side of your helmet/visor to show that they've checked your gear. We will have a large and hairy scrut checking that you've got your signed clothing/group sticker affixed to your helmet before you go on track.
MotorSport Vision (aka Octagon aka Brands Hatch Leisure Group, aka 'Da Management') have asked us to emphasise the merit of back protectors so here it is in suitable emphasised type: Back Protectors are meritorious :-)
Seriously though, speaking as one who was stupid enough to go backwards into a tyre wall at some speed, I must say that I'm very pleased that I was wearing a back protector at the time. It probably made the difference between walking away with a few bruises and something far nastier. So, do yourself a favour and wear a back protector.
Having said that, if you do wear a custom painted Simson Bandit (Hi Mav!) if the helmet appears to be in good nick you shouldn't have a problem. Please be aware though that there are helmets on sale (certain types of Simson car racing helmets for example) that are not suitable for motorcycle use and will not be allowed on track.
The marshals at Cadwell are well versed in what's right and what's not and they have spotted non-motorcycle helmets before and stopped people getting on track. If in any doubt whatsoever, bring a helmet with an ACU sticker.
Anyone expecting to get on the track in a gouged and beaten up 1970's Centurion will have to think again.
Dates on helmets caused a bit controversy in '99 - and if it's over five years old then expect it to get a close examination from the clothing scruts. You should be able to find the date of manufacture on a sticker inside your lid.
Basically, helmet manufacturers recommend that you replace your lid after about five years; cynics would say that they're doing this to increase helmet sales and whilst there might be something in that, there is reason to believe that constant exposure to sunlight, sweat and grime does have a detremental effect on both the outer and inner of the helmet.
However, in this day and age of PYB's who don't ride their bikes to work and won't consider riding when the sun isn't shining, a lot of helmets get very little usage and, if stored away from sunlight, the age of the lid has less meaning than it's general condition.
Again, be sensible. It's your head inside it after all.
Obviously your gloves should be free from holes and missing fingers.
If you have a leather jacket and (leather not denim!) jeans then they must fasten together, with a zip, in such a fashion that the jacket cannot ride up.
The Sales Contract(2018) wording on clothing says:- "Suitably fitting full leathers (one-piece or two-piece with a full zip around the middle (at least hip-to-hip with no gap visible with arms raised above head level)."
Yes I know that kevlar, cordura etc etc are good and very popular (I use them myself on the road quite often). I've been asking them to allow such on track for years but never got anywhere; they say it's their insurers who insist on leathers. Sorry but it's leathers or no tracktime.