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Caravan Jargon Buster


With so much complicated lingo involved with caravans, it might feel as if you need to be something of a caravanning expert to know all the different terminology and what it all means.

Now, with the help of Caravan magazine, you can get up to speed with all the knowledge you need.

Simply follow our guide and you'll soon know a corner steady from a stabiliser.



Understanding caravan jargon

We've listed some of the most common, and most frequently used, terms any caravan owner will come across – with a helpful explanation for each.


7 or 13-pin electrics

New caravans all now come with 13-pin electrics – one electrical socket with 13 pins attaches to the car and deals with all the electrical needs of your caravan while you’re towing. If your car or caravan is equipped to work with the old-fashioned electrics (two sockets each containing seven pins), adapters are available.

85% rule

This is the recommended guideline for matching a car’s weight to the caravan you can tow.

Broadly, as long as your car’s max braked towing limit is not exceeded, you should aim for your caravan and its contents to weigh 85% or less of the weight of your car.

When buying a caravan, the figures you need to use are the manufacturer’s stated kerbweight of the car, and the stated MTPLM figure, so the MTPLM is 85% of the kerbweight or less.

Never tow a caravan that is heavier than the car – it’s dangerous but also likely to invalidate your insurance.


The triangular frame at the front of a caravan, between the main body and the hitch. This is usually covered by a moulded fairing and home to the jockey wheel, tow hitch, handbrake and breakaway cable.


The plastic used to make caravan panels; short for acrylonitrile butadiene styrene.

Actual laden weight

The total weight of a caravan and its contents when being towed. Must not exceed the maximum technically permissible laden mass (MTPLM).


Al-Ko’s ATC Trailer Control is an anti-snaking control system for caravans. It works in a similar way to ESP systems in cars and monitors the lateral movement. If snaking is detected, it briefly applies the brakes to re-establish control of the caravan.


It's now easier than ever to get access to lots more of our caravan practical advice articles, written by experts especially for you. Browse content from the pages of Caravan magazine using our fully searchable digital archive – we've got every issue from February 2013 available.

To start, use the search bar below for whatever you're looking up:




Al-Ko chassis

Many new caravans are built on galvanised chassis made by Al-Ko. The others are made by BPW.


A tent-like structure of fabric over a supporting framework, which provides more living space. It can be attached to the side of a caravan.

You can read more about caravan awnings here

AWS – Approved Workshop Scheme

An approval scheme run by the National Caravan Council (NCC) for engineers working on caravans.


See driving licences.


The number of beds in a caravan.

Blown-air heating

This is a type of heating found on modern caravans. Warm air is circulated by a fan through ducting to heat the interior.

Breakaway cable

A thin steel cable that links the caravan handbrake to the towball, providing a secondary coupling.

If the caravan becomes detached from the car, this breakaway cable will operate the caravan handbrake before the cable breaks, bringing the caravan to a halt. The fitment and use of this safety device is a legal requirement on modern braked trailers.


You can use two different types of LPG gas in a caravan for cooking, and to operate the fridge when you don’t have access to mains electricity. Calor’s blue cylinders are butane – they give a very slight energy advantage over propane and are fine if you only caravan in warm weather.

Cassette blind

Roller blind fitted as part of the window assembly, often with a flyscreen.

Cassette toilet

A form of chemical toilet where the waste holding tank can be accessed from outside the caravan, and removed for emptying without having to transport the whole toilet to the emptying point. Learn how to use it and you'll never look back!

Read our ultimate guide to caravan and cassette toilets here

Cassette toilet chemicals

Needed to help keep cassette toilets functioning properly and smelling fresh. Generally, a pink chemical goes in the top tank, lubricating the flush system, and a blue or green chemical goes into the waste tank. This breaks down waste matter and toilet paper.


Caravan Storage Site Owners’ Association, a nationally recognised body overseeing security measures at caravan storage facilities.

CDP point

This stands for chemical disposal point. It’s the place on a campsite where you empty the waste-holding cassette of your toilet and rinse it out.

Chassis plate

Usually near the door, displaying the VIN number and usually information on the caravan weight. If this is missing, be wary of buying.

Chemical toilet

A self-contained toilet, where the waste material is held in a sealed tank for periodic emptying. Special chemical fluid added to the tank breaks down the waste, and keeps the system odour-free.

CL or CS site

A small campsite, usually taking a maximum of five units. Some have toilet facilities and hook-ups while others have no facilities, so caravans run off their batteries/gas bottles, and their owners rely on on-board washing facilities and toilets.

Corner steady

The ‘windable’ jack built into the corner of a caravan, which is used to stabilise it while in use.

CRiS Check

Like an HPI check for your car, the Central Registration and Identification Scheme tells you if your potential purchase has any problems you need to worry about, such as previous theft, outstanding finance or insurance issues. Modern caravans are marked with a unique 17-digit identity number that is registered centrally.


The separation of the bonded layers of a sandwich construction panel usually due to poor binding during manufacture, or water ingress.


A seating area consisting of a pair (or more) of facing seats, with a (usually removable) table in between, which can often be converted into a bed.

Driving licences

If you passed your test on or after 1 January 1997, you have to take an additional test to match the licence entitlements of drivers who passed their test before that date.

This affects you if the combined weight of your towcar (GVW) and caravan (MTPLM) exceeds 3,500kg; you will have to pass an additional test, the B+E. Many car-caravan combinations fall well below the 3,500kg threshold, so non-B+E drivers still have a large selection of outfits to choose from.

Elevating roof

A feature of some smaller caravans, also called a pop-top. It can provide greater headroom when on site, but gives a lower profile when towing, thus improving fuel economy, access to parking, and ease of storage.

Flame failure device

Gas-powered appliances in caravans should have one of these; it minimises the escape of unburnt gas into the caravan, if a flame accidentally goes out.

Full-service pitch

A pitch which has a fresh water supply and waste water disposal, as well as mains electricity and, often, a TV connection.

Gas locker

A cupboard, accessible only from the outside of the caravan, where gas bottles are stored. This is usually at the front of the caravan under the windows, though there are exceptions.

Grey water

The used water from your shower and taps. This collects in a tank that must be emptied regularly.

Gross train weight

Also known as ‘combined weight’. This is the total laden weight of the car AND caravan, or ‘outfit’. It should not exceed the sum of the caravan’s MTPLM and the towcar’s gross vehicle weight.

Gross vehicle weight

The weight of the vehicle laden to its maximum capacity, as laid down by the vehicle manufacturer.


Glass-reinforced plastic, often used to make the curved mouldings on the front and rear of a caravan. It is more resistant to dints than aluminium, the other main material used for caravan side walls.


A gravel, Tarmac, concrete or other hard surface of a campsite pitch. Preferable in wet or muddy conditions, though you’ll need a grass area alongside for an awning.


This attaches your caravan to the car’s towball.


A security device which prevents the caravan hitch being connected to (or removed from) a towball.

Hook-up (EHU)

A facility on a pitch to connect a caravan to the mains electric supply (see mains hook-up below).

Jockey wheel

The small wheel at the front of a caravan used to support the forward end of the caravan and assist manoeuvring while the caravan is not hitched up.


The empty weight of a motor vehicle as laid down by its manufacturer.

Leisure battery

A 12V battery which powers accessories in the caravan. Available in various ampere/hour ratings, depending on the accessory requiring power. Typically, from 60Ah to 110Ah.

Load index

A number marked on the sidewall of tyres that indicates their maximum load-carrying capacity.

Mains hook-up

This is the campsite’s socket into which you insert your caravan’s mains power cable plug. Some campsites have a hook-up on every pitch. Others have posts supplying two or more sockets.

All new caravans are supplied with mains cables; the usual length of these is 25 metres, which is sufficient for the distance from pitch to power supply on most campsites. Also known as electric hook-up or EHU for short.

Manufacturer’s braked towing limit

The maximum weight of a braked trailer a vehicle will tow, as laid down by the car’s maker.

MIRO (MRO) (Mass in running order)

This is the unladen weight of the caravan before you load it with all your essential holiday kit. The term 'ex-works weight' usually applies to the weight of a new caravan with standard fixtures.

Motor mover

An electric device for manoeuvring a caravan when it is not hitched up. Although it’s a trade name, it’s often used as a generic term.

Want to know more? Check out our ultimate guide to motor movers here


Maximum technically permissible laden mass. With all your equipment, food, clothes, etc, loaded on board, the weight of the caravan must not exceed this figure when being towed.


This is the side of a UK caravan where the entrance door sits. The side nearest the kerb when towing in the UK.


The weight imposed by the caravan on your car’s towball, also known as the static vertical load. Car manufacturers should quote the ideal weight to be imposed on your car’s towball and, for safe towing, you should make sure this weight is adhered to. You can measure this weight with a gauge.


This is the side of a caravan opposite a UK-spec caravan’s entrance door.


Not something you wear – rather it's a caravan and its towing vehicle when considered as a single unit.

Overrun brakes

The basic braking system used by caravans. When the car slows, the hitch head is compressed and operates a rod that runs to the caravan axle, then to the two cables that operate the brake shoes on both wheels. This is designed to prevent the caravan ‘pushing the towcar along’ when descending hills.


Stands for pre-delivery inspection, undertaken before a caravan leaves the manufacturer’s premises to ensure that any faults are found.


An alternative to butane for powering your gas hob/oven and your caravan fridge while you’re neither hooked up to car electrics nor a mains hook-up. Propane has significant advantages over butane, because it can be used effectively in sub-zero temperatures.


A transparent panel in the roof of the caravan that can be opened to provide additional ventilation.

Single-axle caravans

Tourers with two wheels. These are easier to manoeuvre as they can turn on the spot.


Some caravans feature a slide-out side, which is designed to increase interior living space.


Instability on the road where the caravan moves from side to side. This can be caused by high winds, other vehicles overtaking and by poor caravan loading or speeding.


A device to minimise instability, controlling the ease with which the caravan hitch pivots on the towball.

Thatcham approval

Alarms, trackers, safes and other security equipment are rigorously tested by this organisation and given a stamp of approval.


This is the bare metal fastening on the back of your car that directly connects to the caravan, allowing you to tow. These must be fitted by an expert. 

Towing hitch

The ‘cup’ part of the caravan that sits on the car’s towball, connecting the two before towing. This is also the point at which you measure the ’van’s noseweight.


A service helping you to match your car’s kerbweight to a suitable caravan from a huge database of models going back years

Visit our dedicated page to Towmatch here for more information

Twin-axle caravans

Most caravans have one axle, and two wheels – see single-axle. A twin-axle caravan has four wheels and is more stable than a single-axle model; it is less likely to develop a snaking movement.

A twin-axle caravan is also considered easier to reverse because the response to the car’s steering is slower, making it easier to control.

User payload

The difference between the MTPLM and the MIRO. Added equipment can't exceed this weight.

VIN number

See: CRiS. A caravan registration contains useful information, etched on windows, printed on registration documents and displayed on the chassis. The first two letters, SG, indicate it’s a British caravan. A letter then indicates the caravan make (eg Swift is D), and a letter S or T to indicate single or twin-axle.

Water ingress

Otherwise known as a water leak! When water gets into a caravan or its wall/floor/roof panels, it can be difficult, as well as expensive, to repair.

Wet locker

A storage area isolated from the rest of the caravan, for the storage of dirty or wet items.

Wheel lock (integral)

An essential part of caravan security. The best bolt through the wheel and onto a receiver on the caravan axle. There are two types available – one for Al-Ko chassis and one for BPW chassis. 

Buying Your First Caravan, the 2022 special edition is available now. Including everything you need to know about buying your first caravan, with essential guides, top tips and buying advice. Available in both digital and print. Find out more about either the digital edition here or the Print edition here.


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15/04/2021 Share this story   Share on Facebook icon Share on Twitter icon Share on Pinterest icon Share on Google Plus icon Share on Linked In icon Share via Email icon

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