as Robin already mentioned the GPX specification contains a symbol tag (<sym>) for route points (<rtept>).
But as far as I can see at least Garmin devices do not care about the symbol ouf route points - newer devices use an orange flag for ViaPoints and a gray-blue circle for ShapingPoints.
Nevertheless the symbol might be a way to store any information for re-import to kurviger or for use in other programs ( e.g. my converter).
Furthermore adding different symbols for this several point types will help on navigation devices which use the symbol tag (<sym>) of route points and display it on the map.
My personal opinion: I would like to be able to see also in navigation device the information, if a route point was a waypoint or a shaping point in kurviger, furthermore I would like to see the name given to a waypoint or a kurviger shaping point.
Therefore I propose to add a hint at the routepoint name for that: For example ‘WP4’ for the 4th waypoint and a ‘FP7’ for the 7th shaping point. So If I have added a 4th Waypoint with the name ‘Lunch’ in kurviger, the name in the GPX would be ‘WP4 Lunch’.
It could be discussed, if the name prefix for shaping points should be ‘FP’ for german variant (Formpunkt).
I just checked: The app uses “Formpunkt” in german version, the website uses “Shaping-Point” in german version - perhaps it would be good to use the same terms in app and website (shall I add a seperate topic for that ?). In that case I would prefer to use “shaping-point” and - of course - the prefix ‘SP7’ in all language versions.
I think the name of the route point can be seen in any navigation device - therefore putting that suffixes to the name works on all navigation devices, so you can see if a point is a waypoint, a shaping point or if it has been added by the GPX export.
This prefixes might be also useful for Garmin-specific GPX export, even, if waypoints are converted to Garmin ViaPoints.
Reason: See if the Garmin ShapingPoints are Kurviger shaping-points (grey marker in app, smaller black marker on website) ore are points added by GPX export. Furthermore when re-importing GPX to kurviger this information also will be useful.