XPointer is a system for addressing components of XML-based Internet media.
[3][5] The XPointer language is designed to address structural aspects of XML, including text content and other information objects created as a result of parsing the document.
Thus, it could be used to point to a section of a document highlighted by a user through a mouse drag action.
During development, and until 2016, XPointer was covered by a royalty-free technology patent held by Sun Microsystems.
This is similar to a simple XPath address, but subsequent steps can only be numbers representing the position of a descendant relative to its branch on the tree.