FYI
Groundspeak plans to update the Geocaching.com XSD to include useful geocache information not found in the current schema. Application developers will please be aware that these changes are coming and take steps to prepare your applications for them.
Changes include:
"Unknown" caches will now be referred to as "Mystery" to match the cache type designation on Geocaching.com
All elements in text fields will be wrapped in CDATA tags (http://www.w3schools.com/xml/xml_cdata.asp)
"Premium Member Only" cache status added
Cache Favorites Points added
Personal Cache Notes added
URLs for cache images added
The update is currently scheduled to go live on August 2nd, 2011. In the next few weeks Groundspeak will provide a sample XSD for developers to review.