This format can...
read and write waypoints
This format is derived from the xcsv format, so it has all of the same options as that format.
This is a format for creating data to be read by Microsoft Streets and Trips. It's been exercised on versions from 2003 through 2008. Detailed instructions on how to use it, including preserving hyperlinks, are at gpsbabel.org
We have an additional page describing how to solve the traveling salesman problem with Streets & Trips to efficiently optimize a trip with many stops, such as is often made by geocachers.
Since modern versions of Streets and Trips support reading GPX, this format is probably not so useful.