These conferences have a two-stage submission procedure: first you submit a short abstract and on basis of that you are (hopefully!) invited to submit a short paper. This paper is then published in a proceedings book, which is available at the conference. As a long-time conference participant and a previous congress organizer, I have lots to say about this concept… On a positive note, it’s always an interesting book. And being responsible for editing one really made me a much more efficient editor!