The Metadata Authority Description Schema (MADS) is a hierarchical XML-based bibliographic description schema created by the Library of Congress’ Network Development and MARC Standards Office. MADS serves as a companion to the Metadata Object Description Schema (MODS) to provide metadata about the authoritative entities used in MODS descriptions.
XML Path Language (XPath) is a query language employed by the XML forms in the repository to both write the proper nodes to the MADS XML datastream and read the nodes from that datastream t to display in the form.
How XPath Syntax and XML match up (color coded):
XPath Syntax noted in metadata mapping sheets and employed in XML forms
mads:autority/mads:name[@type="corporate"]/mads:namePart
Resulting XML in MADS datastream
<mads xmlns="http://www.loc.gov/mads/v2" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mads="http://www.loc.gov/mads/v2">
<authority>
<name type="corporate">
<namePart>Archive of the Indigenous Languages of Latin America</namePart>
</name>
</authority>