Sadly, during the course of this work, our co-author and colleague, Brunella Monsignori Fossi died suddenly and prematurely. Her enthusiasm, support and friendship is a great loss not only to us but to the whole of the solar and stellar physics communities.
Acknowledgements
The success of this database has been dependent on a number of researchers who have made their data available to us in electronic form, often in advance of publication. These include W. Martin and A. Musgrove (NIST), A. Bhatia (GSFC), H. Zhang and A. Pradhan (O.S.U.), R. Sampson (PSU), K.G. Widing (NRL), K.A. Berrington, J. Pelan, and C. Ramsbottom (QUB). KPD acknowledges financial support for this project from the Ultraviolet, Visible and Gravitational Astrophysics program of NASA. HEM and PRY acknowledge the financial support of PPARC. We would also like to thank the referee, Dr. Rolf Mewe, for his careful reading of the manuscript.