You can't trust the labeling is the problem when you shop at a supermarket. In the UK if the label says something is 'free range' or is 'sourced locally' or has 'such and such an ingredient' it could well not be any of those.
http://www.guardian.co.uk/environment/2011/feb/26/local-food-labelling-misleading-consumers
http://www.thepoultrysite.com/poultrynews/19718/businessman-jailed-over-egg-labelling-scandal
the UK is pretty lax, but the EU overall is not
The European Union regulates marketing standards for egg farming which specifies the following (cumulative) minimum conditions for the free-range method:
hens have continuous daytime access to open-air runs, except in the case of temporary restrictions imposed by veterinary authorities,
the open-air runs to which hens have access is mainly covered with vegetation and not used for other purposes except for orchards, woodland and livestock grazing if the latter is authorised by the competent authorities,
the open-air runs must at least satisfy the conditions specified in Article 4(1)(3)(b)(ii) of Directive 1999/74/EC whereby the maximum stocking density is not greater than 2500 hens per hectare of ground available to the hens or one hen per 4m2 at all times and the runs are not extending beyond a radius of 150 m from the nearest pophole of the building; an extension of up to 350 m from the nearest pophole of the building is permissible provided that a sufficient number of shelters and drinking troughs within the meaning of that provision are evenly distributed throughout the whole open-air run with at least four shelters per hectare.[10]
Otherwise, egg farming in EU is classified into 4 categories: Organic (ecological), Free Range, Barn, and Cages.[11]) The mandatory labelling on the egg shells attributes a number (which is the first digit on the label) to each of these categories: 0 for Organic, 1 for Free Range, 2 for Barn and 3 for Cages.[12]
There are EU regulations about what free-range means for laying hens and broilers (meat chickens) as indicated above.