As venue we could again win the Hotel Hennies in Isernhagen near Hannover, which can be reached from all over the world. We were able to negotiate good conditions with the hotel, which should be affordable for most interested parties even in these difficult times. So we can surely expect participants from far away countries again, which is the special attraction of this event. We are looking forward to seeing you all again and would like to thank all those who have confirmed their attendance. Many thanks especially to all sponsors, who make the L-Number-Days in this form possible. The basic structure of the lectures is already fixed with well-known speakers, who promise again a really interesting and varied program. We will publish the exact program as soon as all details are clarified. We hope that the 7th International L-Number-Days will again be as interesting and successful and would be very happy to welcome you!