. XPath is used for locating XML content within an XML 
document; XPointer is the standard for addressing such content, once located. 

interesting acknoledgement: "Finally, to my wife Toni: to paraphrase Don Marquis's dedication to his Archie and Mehitabel, thanks "for Toni knows what/and Toni knows why." 

w3c invented and manage xpath and xpointer

"The schemedata contents of pointer parts vary with their schemes, and the XPointer Framework itself does very little to constrain them. Each scheme specification provides its own set of rules describing how its schemedata is to be interpreted."