Hi, I'm currently evaluating xwiki. My goal is to develop a data maintenance system for books and authors data. Two entities, BOOK and AUTHOR, have a many-to-many relationship. The new system should provide an ability to maintain the attributes of each entity as well as the relationship between them using forms. There are a large number of existing data, which are sourced from other systems and I'm considering to store them using custom mapping in XWiki. Now I wonder how I should store the many-to-many relationship in XWiki database. Is it a right approach for XWiki to introduce the traditional intersection table? Also, I'd like to know the subsequent steps to follow. I need to create a .hbm file and define a many-to-many mapping, right? And next...? Any hint would be greatly appreciated. Thanks, ebi