Google egen KML dokumentation ...
Googles KML documentation ...
This section contains an alphabetical reference for all KML elements defined in KML Version 2.2, as well as elements in the Google extension namespace. The class tree for KML elements is shown below. In this diagram, elements to the right on a particular branch in the tree are extensions of the elements to their left. For example, Placemark is a special kind of Feature. It contains all of the elements that belong to Feature, and it adds some elements that are specific to the Placemark element.
KML is an open standard officially named the OpenGIS® KML Encoding Standard (OGC KML). It is maintained by the Open Geospatial Consortium, Inc. (OGC). The complete specification for OGC KML can be found at http://www.opengeospatial.org/standards/kml/.
The complete XML schema for KML is located at http://schemas.opengis.net/kml/.