Those interested in presenting a paper or poster at the conference should submit an abstract of no more than 250 words by December 31, 2018.
All fields on the webpage should be completed, including checking whether you wish to present orally, with a poster, or with either. Oral presentations will be about 15 minutes and will be part of thematic moderated sessions.
as per https://github.com/Daniel-Mietchen/events/issues/511 and http://www.preaportal.org/conference/submissions/ :