There's a lot of information available on the different styles of real ale available today - not least CAMRA's own online guide and the invaluable Good Beer Guide (available here), so we're not trying to reinvent the wheel here.

Instead, and to help you find your way around our Programme (handed out free on admission to the festival), here are the symbols we use and a summary of the sorts of beers you can expect to find them describing, along with some examples (starting with local breweries) from our 2011 Beer List.

The word "bitter" is a broad term when it comes to real ale, with many non-ale drinkers applying the word as a catch-all description. In technical terms, bitters developed at the end of the 19th century as larger brewers sought beers that could be easily distributed amongst their estates of tied pubs and would be ready to serve within a few days of reaching the cellar.

Originally a variation on pale ale, use of slightly darker malts tend to give a bronze or copper colour and a full palate. Typically, an ordinary bitter would be 3.9% or less, a "best bitter" would weigh in at 4-5% and a "strong" or "special" (see below) would come in at 5%+, but none of these are hard and fast rules.

We also list most pale ales, including IPA ("Indian Pale Ale"), in the "Bitter" category (although some may sneak under the radar as Golden Ales - see below). Pale ales are traditionally brewed with lighter malts for colour, whilst IPAs were traditionally brewed to a strong ABV with lots of hops: both of these factors aided preservation for the long sea journey around the Cape of Africa en route to India for the enjoyment of the colonialists.

The Sussex Beer & Cider Festival uses a white pint glass symbol to denote bitters that are less than 5% ABV, and examples have included:

• Hepworth Prospect (4.5%)
• Fullers Gales HSB (4.8%)
• Triple fff Alton's Pride (3.8%)

We use a lilac pint glass symbol to denote stronger bitters (but not very strong ales such as barley wines - see below), which in the past has included the likes of:

• Langham Special Draught (5.2%)
• Butcombe Brunel IPA (5%)
• Crouch Vale Amarillo (5%)

A very traditional beer style that dipped in popularity but is now enjoying a revival and even benefits from an annual "Mild in May" promotion. The word "mild" refers to its less bitter taste, rather than strength: although today's specimens often weigh in at less than 4%, there are good examples at 6%-plus. Contrary to popular belief, a mild doesn't have to be dark in colour either: each May, Harveys brews an excellent light mild called "Knots of May" which is well worth hunting down.

Some examples of milds include:

• Arundel Sussex Mild (3.7%)
• Bank Top Dark Mild (4%)
• Surrey Hills Hammer Mild (3.8%)

Golden Ale has only come to prominence in the past few years, and has been widely targetted at younger drinkers tempted to switch from lager. In fact, the earliest examples originated as early as the 1980s, but popularity of this ale type has soared (with Fullers developing its Discovery ale as a drink to be served at a cooler temperature than traditional ales as a summer thirst-quencher). Flavours tend to be light and easy-drinking, although often with unusual hop combinations to add to the taste. A good style for a new real ale drinker to start with!

Some good specimens include:

• Dark Star American Pale Ale (4.7%)
• Langham Hip Hop (4%)
• Hogs Back HOP (4.6%)

Old Ale dates from the centuries-old tradition of maturing ale for lengthy periods in wooden vessels called tuns, which imparted a slightly acidic sourness to the beer due to wild yeasts creeping in via the wood. Usually, but not always, dark and often on the stronger side. Luckily for us, many Sussex breweries have an excellent pedigree in this particular style!

Stout and porter share a common evolution as drinks originally brewed for London market workers, although WWI restrictions on malting led to Ireland becoming market leaders in this style. Both beer styles are characterised by their dark colour and rich flavours, evoking dried fruits, coffee, liquorice and molasses, all balanced with hoppy bitterness. Unlike more commercially available stouts that pub-goers may be more familiar with, the real cask versions are not served from nitrogen kegs and will lack the artificial creaminess, although they are all the more drinkable (and tasty) for it! CAMRA's "beer with personality" campaign leaflet explains that one distinction between stouts and porters is the use of roasted barley by the former compared to the dark malts used by the latter; the other key difference being that "stout porters" tended to be stronger versions than normal porters. Imperial stouts (which we tend to class as Strong Ales - see below) are examples of stouts that brewed to be particularly strong so as to survive the sea journey to Russia, where it was rumoured to be a particular favourite of the tsars!

The following examples of each style have previously graced the festival:

• King's Old Ale (4.5%)
• Weltons Horsham Old Ale (4.5%)
• Hogs Back O.T.T. (Old Tongham Tasty) (6%)
• Hammerpot Bottle Wreck Porter (4.7%)
• Elland 1872 Porter (6.5%)
• Oakleaf Piston Porter (4.6%)
• Dark Star Espresso Stout (4.2%)
• Hop Back Entire Stout (4.5%)
• Whitstable Oyster Stout (4.5%)

Barley Wine developed as a result of England's historic conflicts with France, to give the landed gentry a patriotic alternative to French wines (we have wine from England too these days - some of which will be available at the Festival!). The style is strong (usually over 10%), requires lengthy maturation and tends to be drunk in smaller quantities as a "sipping beer"; it tends to be a minority beer style, and may be pushed even further to the fringes thanks to plans to increase taxation on the production of stronger beers.

We also use the black pint glass symbol to denote any particularly strong ale.

Examples of such styles include:

• Adur Merry Andrew (6.2%)
• Ballards Duck House (9.7%)
• Dark Star Imperial Stout (10.5%)
• Brewdog Hardcore IPA (9%)
• Goachers 1066 Old Ale (6.7%)

Sometimes, a beer defies normal classification. This may be due the use of exotic ingredients or adjuncts, or because it's in the vanguard of what will, in time, become a recognised style of its own.

What we classify as "unusual" could include Scottish heather or peat, smoked malt, ginger or other fruit or even a "cask lager". Here are some previous examples:

• FILO Ginger Tom (4.6%)
• Weltons Flower of Scotland (4.7%)
• Bowmans Elderado (3.5%)
• Harviestoun Schiehallion (4.8%)