A data system has a data structure with a posting corresponding to a set of pieces of content to be served. The posting includes a description of each piece of content including a name, a type, and a location thereof. The posting is presented to a user according to a pointed-to template. The template includes a placeholder within which each piece of content is to be presented, and positioning information setting forth a layout position for each placeholder. The template points to a separate content definition information module that includes content definition information for each placeholder including the name and type of the corresponding piece of content. Such name and type matches a corresponding name and type as set forth in the posting.