A black and white poster, in landscape mode. The poster says: "Lisp, send more parentheses. Interested in Lisp and related projects? Come and meet us at the Lisp assembly." The style vaguely resembles the official 38c3 styleguide. A QR code is also included that links to https://38c3.c3nav.de/l/lisp/.
https://social-coop-media.ams3.cdn.digitaloceanspaces.com/media_attachments/files/113/720/065/311/228/101/original/dc43612f91538c44.jpg