The XML standard allows for namespace domains, such that element names (tag names) belong to either the empty (null) namespace or in a namespace that belongs to a particular XML grammar. Namespaces are identified by a uniform resource identifier (URI) that is fashioned, similar to a URL, to be guaranteed to be unique.
The <reference> element can include two elements that belong to the
World-Wide Web Consortium (W3C)'s XLINK protocol; they are defined with an
xlink: prefix which actually refers to the
http://www.w3c.org/1999/xlink URI. If external links to documents will be
included in a DAVE-ML document, the top-level element (currently
<reference> must include a namespace
declaration (which looks like, but technically is not, an attribute):
<DAVEfunc xmlns:xlink="http://www.w3.org/1999/xlink">
Similarly, the MathML elements are normally defined in a MathML namespace, so any calculation defined using MathML notation should be conducted inside the MathML namespace:
<math xmlns="http://www.w3.org/1998/Math/MathML">
If it is necessary to embed DAVE-ML inside another XML document, the DAVE-ML namespace can be used; this can be defined uniquely as
xmlns:dml="http://daveml.nasa.gov/2008/DAVEML">
but note that this is not a URL; http queries at that address may not lead to any useful information.
$Revision: 348 $