NamespaceRegistry - Jackrabbit Wiki

The following list is a registry of common namespace mappings found in JCR applications. Note that the listed prefixes are not universal, as some repositories can use different mappings for the same namespaces. All prefixed names on this wiki and on the Jackrabbit web site use these mappings unless otherwise specified. Unless there is a good reason to do otherwise, you should avoid using these prefixes for different namespace mappings.

Prefix	Namespace URI	Comments
		The default namespace with an empty prefix and an empty namespace URI.
xml	http://www.w3.org/XML/1998/namespace	The XML namespace. Should not be used in JCR content to avoid problems with XML exports.
xmlns	http://www.w3.org/2000/xmlns/	The XML namespace namespace. Should not be used in JCR content to avoid problems with XML exports.
jcr	http://www.jcp.org/jcr/1.0	Namespace of standard node and property names specified in JSR 170.
nt	http://www.jcp.org/jcr/nt/1.0	Namespace of the standard primary node types specified in JSR 170.
mix	http://www.jcp.org/jcr/mix/1.0	Namespace of the standard mixin node types specified in JSR 170.
sv	http://www.jcp.org/jcr/sv/1.0	The JCR system view namespace. Should not be used in JCR content to avoid problems with XML exports.
rep	internal	Internal Jackrabbit namespace used for internal node types.
jlib	http://jlibrary.sourceforge.net	The jLibrary namespace.
mgnl	http://www.magnolia.info/jcr/mgnl	The Magnolia namespace.
dc	http://purl.org/dc/elements/1.1/	The Dublin Core Element Set v1.1 namespace
dcterms	http://purl.org/dc/terms/	The Dublin Core Terms namespace
fn	http://www.w3.org/2005/xpath-functions	The XQuery 1.0 and XPath 2.0 function namespace
fn	http://www.w3.org/2004/10/xpath-functions	The XQuery 1.0 and XPath 2.0 function namespace (October 2004 version)
xs	http://www.w3.org/2001/XMLSchema	The XML Schema namespace

Feel free to add entries to this list.