Because JSP files can be converted to XML, it is important to understand the relationship of tags and elements. A tag is simply a short piece of markup that is part of a JSP element. A JSP element is a unit of JSP syntax that has an XML equivalent with a start tag and an end tag. An element can also contain other text, tags, or elements. The technique for creating custom tags is described in the JavaServer Pages Specification for version 1.1.
Empty prefixes are illegal.
If you are developing or using custom tags, you cannot use the tag prefixes jsp , jspx , java , javax , servlet , sun , and sunw , as they are reserved by Sun Microsystems. Inc. All rights reserved.