I have a Java app where I have to validate xml file provided by the user against the XSD schema. In my application I use SAX parser. I tested it with several test xml-files and was satisfied with the result. However, let's say for fun, instead of input xml file I put the validating xsd schema itself. Strangely, it passed the validation. I am wondering if this is the right behavior. Simply put, should xsd schema file pass validation against itself?