Until now I did not give much thought to using and saving GPX data. I was able to do what I wanted and I was a happy camper. Now that I am working more with the ACA GPX files I have dug into the GPX XML specifications. I had to make modifications to the way I was handling the data.
As I understand the GPX files, the basic foundation is the waypoint-type (a variant of the point-type) which describes waypoints, points of interest, and geographic features. The two attributes, longitude and latitude, defines the geographic location. The encapsulated data in the waypoint goes onto to more fully define the various aspects and properties of the waypoint-type.
Looking at an ACA GPX file with resources the is many waypoints, and not points of interest or other waypoints. These waypoints are again found in the <rte> sections as <rtept> entries. The ACA GPX files don’t seem to have a <trk><trkseg><trkpt> section as I believe they were developed using maps and not a gps device.
However if there was a <trk><trkseg> section the waypoints would show up again as <trk><trkseg><trkpt> entries. So theoretically the <rte> and <trkseg> could be construed to be synonymous. But there are limits to the number of route points allowed for Garmin devices. Subsequently the <trk> <trkseg> would be a sparse track.
The goal is to use the ACA GPX route files to create a viable track section with directional waypoints and cue sheets. The ACA waypoints are non directional. No right turns or left turns as they serve both directions of travel.