Aha - found it - reproduced below. This was kind of aimed at first timers, but hopefully it will be of some use!
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So, you've got your Probans, your Boots, your Gloves, your raingear, your Understuff and your First Aid Kit. You're good to go right? Well yes, but there are some other things that aren't strictly on the kit list that are very useful to have. Here's a list of some of the other things that are handy to have around!
Water
Never ever go out on post without a good supply of water. You can get dehydrated even on the coldest and wettest of days. If you get too dehydrated, you'll faint. Then the Rescue Crew will arrive, snigger at you and stick a big needle in your arm.
Snack
Ideally you should always have your lunch with you on post but we know that doesn't always happen. Always keep some fruit (or a chocolate bar) and a small, salty snack like crisps or peanuts, with you. The fruit sugar and the carbohydrates in the crisps/peanuts will help keep your blood sugar level. The salt in your snack will also help with combatting dehydration (obviously, if you have special dietary requirements, then ignore anything in here that you're not allowed to have!!!).
It is generally considered a bad idea to overdose on crisps, chocolate and fizzy drinks.....and the less said about pork pies the better!
Whistle
When you get in trouble and you don't know what to do, give a little whistle....Well it won't get you Jiminy Cricket, but it will get the attention of other marshals. A whistle is a vital piece of kit. You can scream your head off at someone across the track, but they won't hear you. Blow a whistle and you'll get their attention. Don't forget, the whistle is not just to bring attention if you need assistance - it's also to let other marshals know they're in danger. Get a decent referee type whistle. These mostly come with a neck lanyard, but this isn't ideal. If you must get a round the neck one, then make sure it has a breakable tab so that if it DOES get caught in a driver's wheel, it's not going to tighten and throttle you! Alternatively, just attach your whistle on a plastic "bungee" cord to your overall zip.
Safety Glasses
You can pick these up at any hardware or DIY store for about €5. They are a wise investment. Even if you wear glasses ordinarily, you can still be hit by bits of flying gravel so it's a very good idea to have these in your bag.
Ear Defenders
Again you can pick these up at any hardware or DIY store for about €5. Not so necessary for the standard Irish classes - although they can be pretty loud - but absolutely essential for events like the FIA Sportscars.
Suntan Lotion
No I'm not joking!
Even on cloudy days, you'd be surprised how quickly you can burn if you're out all day. At the end of the day, you'll find people wandering around saying "I have Track face". Track Face is a combination of sunburn, rainburn and waterburn. Always bring suntan lotion. Even handier are the new suntan wipes that you can buy - much easier, particularly if you have dirty hands and don't want to wipe dirt all over your face!
Moisturiser/Hand Cream
Another protector from the dreaded "Track Face"! Even if there isn't a trace of sun, wind and rain can still make you feel like you've got burned. A good moisturiser with built in UV protection is a good solution. For all you boys out there, it's not a "girly" thing - you'll find that Nivea produce a very good moisturiser for men! Hand Cream is also useful - I use Atrixo myself, but any good handcream product will do.
Insect Repellent
Some time around May, you will meet the gnats who live in the tyre walls. They're annoying and breathing them in can be very unpleasant. Sweat attracts them particularly and they do seem to have a fondness for the smell of damp Proban as well. A spray of repellent around the hat works wonders!
Deodorant
A personal one this - but remember, if it gets hot and you're going to be running around, no matter WHAT the Sure adverts tell you, you're going to sweat. No-one will mind much if you're a bit sweaty - but if you're the sort of person that is bothered by this, it's probably worth investing in a spare can of deodorant or possibly deodorant wipes.
Multitool
You will almost never see a marshal without one of these. Choose one that's sturdy and has a scissorlike cutting device for things like cutting seatbelts. A word of advice - don't spend a fortune on something like a Leatherman. Tools can get damaged or lost and you will get just as much use out of a €20 version from Millets as you will with a hand-crafted, gold-plated article from Switzerland!
Torch
But it's not dark.....Well that's what I said when I asked a member of Rescue why they always carried a torch on their belt. As always there was method in the apparent madness. When a driver is sitting in a tight single-seater complaining they can't move their feet, it's going to be too dark to see if there's a problem - that's where your torch comes in...!
Tissues
Even if your runny nose doesn't bother
you, spare a thought for the members of your crew who really don't want to watch you leaving snail trails on the arm of your probans...!
Dustmask
Anyone who's ever done a Rallycross on a dry circuit will tell you that this little item can make your life a whole lot more pleasant! Nothing fancy needed - you can pick up packs of these at any DIY store.
Plastic Sack
There is no such thing as a waterproof kitbag. Trust me on this - I've tried every combination of bag type and I've still ended up with soggy sandwiches. The only method that has ever worked for keeping my bag dry is to put it in a nice, big binbag. Works pretty well!