Hi Where can I find out more about the wheres and whys of mendix element creation in the document model? For example, starting at the very beginning with a simple project: <!-- anatomy of a mendix page --> <!-- in the following page i added a layout with just a blue content pane --> <!-- you cannot class this, so i classed the white surface of the layout with scoobydoo --> <!-- i used the layout on a page, and classed what i believe to be the outermost --> <!-- element of the page with chewbacca --> <!-- the result is a div with both classes for one element --> <!-- questions: --> <!-- 1. why are the classes shared --> <!-- 2. what is the purpose of the first mx-placeholder div created between the first --> <!-- widget on the page (the microflow label) and the div shared between the layout --> <!-- and the page? --> <!-- 3. what is the purpose of the second mx-placeholder div created between the first --> <!-- widget on the page (the microflow label) and the div shared between the layout --> <!-- and the page? --> <!-- --> <!-- thankyou --> <DOCTYPE! html> <html class="dj_gecko dj_ff37 dj_contentbox"> . . . <body class="profile-desktop role-administrator" dir="ltr"> <div id="content"> <div style="" focuscycle="true" focus-id="mxui_wm_focus_Box_0" class="mx-page scoobydoo chewbacca"> <div data-mx-placeholder="main" class="mx-placeholder"> <div class="mx-placeholder" data-mx-placeholder="eb6fb705-2234-4be4-8093-e55b55846509"> <div widgetid="MicroflowLabel_widget_MicroflowLabel_0" focusindex="0" style="" mxid="1" id="MicroflowLabel_widget_MicroflowLabel_0" tabindex="0" class="mx-name-microflowLabel1" data-mendix-id="1">test</div> </div> </div> </div> </div> . . . Thankyou very much