+++ /dev/null
-******************************************************************************
-Extensions of the XML specification
-******************************************************************************
-
-
-==============================================================================
-This document
-==============================================================================
-
-This parser has some options extending the XML specification. Here, the options
-are explained.
-
-==============================================================================
-Optional declarations instead of mandatory declarations
-==============================================================================
-
-The XML spec demands that elements, notations, and attributes must be declared.
-However, there are sometimes situations where a different rule would be better:
-If there is a declaration, the actual instance of the element type, notation
-reference or attribute must match the pattern of the declaration; but if the
-declaration is missing, a reasonable default declaration should be assumed.
-
-I have an example that seems to be typical: The inclusion of HTML into a meta
-language. Imagine you have defined some type of "generator" or other tool
-working with HTML fragments, and your document contains two types of elements:
-The generating elements (with a name like "gen:xxx"), and the object elements
-which are HTML. As HTML is still evolving, you do not want to declare the HTML
-elements; the HTML fragments should be treated as well-formed XML fragments. In
-contrast to this, the elements of the generator should be declared and
-validated because you can more easily detect errors.
-
-The following two processing instructions can be included into the DTD:
-
--
- <?pxp:dtd optional-element-and-notation-declarations?>
-
- References to unknown element types and notations no longer cause an error.
- The element may contain everything, but it must be still well-formed. It may
- have arbitrary attributes, and every attribute is treated as an #IMPLIED
- CDATA attribute.
-
--
- <?pxp:dtd optional-attribute-declarations elements="x y ..."?>
-
- References to unknown attributes inside one of the enumerated elements no
- longer cause an error. Such an attribute is treated as an #IMPLIED CDATA
- attribute.
- If there are several "optional-attribute-declarations" PIs, they are all
- interpreted (implicitly merged).
-