The 12th international Workshop on Computational Logic in Multi-Agent Systems (CLIMA XII) invites submissions for a special session on Norms and Normative Multi-Agent Systems. The submission deadline is April 4 (for abstracts) and April 8 (for papers). CLIMA XII is affiliated with IJCAI 2011 and will take place in Barcelona, Spain, July 17-18, 2011. For more information see the workshop website.