A lot of the examples in this chapter have converted XML into HTML, and you might have wondered how an XSLT processor knows to omit the <?xml?> declaration from the beginning of such output documents. It turns out that there's a special rule here: If the document node of the output document is <HTML>, the XSLT processor knows that the output document type is HTML and writes the document accordingly.
In fact, you can specify three types of output documents:
XML— This is the default, and such documents start with an <?xml?> declaration. In addition, entity references are not replaced with characters such as < or & in the output document; the actual entity reference appears in the output.
HTML— This is standard HTML 4.0, without ...