Notations are how the Document Type Description (DTD) records hints about the format of an XML "unparsed entity" -- in other words, non-XML data bound to this document type, which some applications may wish to consult when manipulating the document. A Notation represents a name-value pair, with its nodeName being set to the declared name of the notation.
Notations are also used to formally declare the "targets" of Processing Instructions.
Note that the Notation's data is non-DOM information; the DOM only records what and where it is.
See the XML 1.0 spec, sections 4.7 and 2.6, for more info.
Level 1 of the DOM does not support editing Notation contents.
@version
@since PR-DOM-Level-1-19980818.