How to create custom element with custom attributes in FrameMaker 13

Hello. Is there a way to create custom XML element(and customized list of attributes) in FrameMaker in a way, which the framemaker will open the xml file and validate it successfuly. For example I want to have xml element <table10> with attributes class,id,pr etc, but when I use the new feature since version 11 called "XML View" and modify the code - after a while the new element staies, but the attributes dissaper and in Structured view the element "table10" is in red. After save and open - message for validation fail apper, but the file opens and again table10 is in red. I mean is there way to learn Adobe FrameMaker for the existance of my own elements and their attributes? I am using Structured FrameMaker and do not have experience over Unstructured and XML Author.