Practically, larger libraries use their own internal regulations taking into account the character of the particular collection. We should add that digital map collections have been made in the form of computer files which also have to be properly described for retrieval purposes, i.e. classified and catalogued. In many libraries, automation of map collection processing and providing access has been implemented. The scope of problems related to the classification of cartographic materials is broad and concerns some basic matters. First of all, we should specify a lack of uniform classification criteria.
Classification is the most common tool of map collection organisation.
It should be closely related to the properties of cartographic materials. Under the current classification systems for cartographic materials, geographic criteria have been adopted as the basis of categorisation. In addition, such information is available from distributed databases or through the Internet. The issues mentioned in this article concern the selected problems of organisation and representation of knowledge about map collection in the context of map retrieval systems in libraries. Representation of knowledge occurs here at the level of cartographic information when we perceive maps as the source of information, and at the level of its description when we perceive them from the viewpoint of information about maps and collections of such materials kept in libraries or networks.