The information available through the Internet continues to proliferate. As it does so, it gains increasing importance and legitimacy throughout the scientific community. Researchers can obtain information from the network just as easily as from a library. The network is thus growing into one of a multiplicity of sources of knowledge of use to the scientific community. Above all, it is about to become an invisible everyday desktop work tool (much in the same way as wordprocessing programs did before it). Hence the increasingly pressing need for systematic, standardised mechanisms to identify, locate and describe the network's information resources.