This schema specifies hierarchical keyword XMP properties used by Adobe Lightroom.

• Exiv2 keys are Xmp.lr.<Property>
• The schema namespace URI is http://ns.adobe.com/lightroom/1.0/
• The preferred schema namespace prefix is lr

Reference: Adobe Lightroom Keywords

Property	Label	Value type	Exiv2 type	Category	Description
hierarchicalSubject	Hierarchical Subject	bag Text	XmpBag	External	Adobe Lightroom hierarchical keywords.
privateRTKInfo	Private RTK Info	Text	XmpText	External	Adobe Lightroom private RTK info.