For looking up data bases, the user should be able to refer to already prepared complex queries by simple UDIs. A moe advanced user should also be able to prepare a complex query himself, store it (interpreted language!) in his local filing space, and use it through a simple UDI.
[The (paper) document "HyperText and CERN" describes the problem to be solved at CERN, and the requirements of a system which solves them. That information is not repeated here.]