Moments after mankind started to make moveable physical records describing the world about them people started to store and arrange the records in logical order. Thereafter, records were copied and translated and simple catalogues of collections were compiled. Others, working from these records and from oral sources compiled lists, dictionaries and encyclopaedias. As the means of communication developed from the first revolutionary invention of writing to other revolutions in communication methods, notably printing with moveable type and the computer, techniques of knowledge organization became more sophisticated and powerful. In the first half of the 21st Century we are faced with an unprecedented communications overload and the full range of knowledge organization techniques need to be deployed, further developed and applied.