Part 1 High latitude ionosphere: electron density - ionospheric mapping in the polar and equatorial zones, K. Rawer; including auroral oval boundaries in the IRI model, D. Bilitza; high latitude digisonde measurements and their relevance to IRI, B.W. Reinisch et al; EISCAT data base for ionospheric modelling - F-region and topside ionosphere, P.N. Collis; main ionization through parameters for ionosphere modelling by HF radio network observations, D.V. Blagoveshchensky and T.D. Borisova; typical behaviour of the high latitude lower ionosphere, M. Friedrich and K.M. Torkar; temperatures and ion composition - morphology of electron temperature in the high latitude plasmasphere, K.-I. Oyama and T. Abe; high latitude ion composition, J.M. Grebowsky and W.R. Hoegy; vibrational kinetics of molecular nitrogen and its role in the composition of the polar thermosphere, G.A. Aladjev and A.S. Kirillov. Part 2 Mid and low latitude ionosphere: a regional model of E- and F-layer critical frequencies, G.A. Zherebtsov et al; on information obtainable from digital ionograms and their corresponding real-height profiles, L. Bossy; the global NO distribution computed on the basis of a dynamic 3D-model and implications on the winter anomaly of the D-layer, G. Sonnemann et al. Part 3 Generalities: EISCAT catalogue specification of the ionospheric quiet and disturbed conditions, T.L. Gulyaeva; definition of disturbance and quietness with topside ionosonde data, T.L. Gulyaeva et al; EISCAT and the EISCAT data base - a tool for ionospheric modelling (E- and D-region), K. Schlegel; a comparison between electron content deduced from the IRI and that measured by the TOPEX dual frequency altimeter, T.R. Robinson and R. Beard.