When one uploads a GPS trace, they are given the options of uploading it as “Identifiable”, “Public”, “Trackable”, or “Private”. I think that I understand “Private”, and “Trackable”: “Trackable” provides extra info that can be used to discriminate the “newness” of the GPS trace from its timestamps; however, the timestamps could also be used to correlate the uploader with a real identity. Whereas “Private” is less useful, in the same sense, without the timestamps, it provides added public privacy for the uploader. But what is the purpose of “Identifiable” and “Public”? Why would one intentionally choose either of those? The only rationale that I can think of is so that one can associate their user’s reputation with their uploaded trace (ie the trace’s trust level). I’m curious how others interpret the use of these 4 options.
Hi !
Did you check the relevant wiki page : Visibility_of_GPS_traces ?
It’s quite clear, I think, about the difference between each option (way better than it used to be).
As to why one should choose to link the traces to their account, the first use I think of is the same as with data edits, other users can send you messages about your traces, for clarification or removal if necessary… It might also help to filter only your (or someone else’s) traces when editing in JOSM for example, and get rid of the noise (in some places there are a lot of traces). I’m sure there are other use cases. 
Best regards.
Erm - I think it could perhaps do with a little extra clarity?
The key questions of “if I choose option X, what and where will I see my traces” and “what will other people see” aren’t answered very clearly (at least to me - and I actually know how it works). A statement like “The trace will be linked to your user account when accessed via the API” is basically meaningless to most people who will read that page. They don’t use APIs - they use the OSM website, other websites, and applications on PCs and phones.
That said it’d be a real challenge to rewrite it to be clearer and shorter (it’s arguably too long already).
Maybe an example would help. Most of the GPS traces I upload tend to be “private”. They contain (in Garmin terms) lots of waypoints, the occasional route and usually one track each.
When I’m editing based on a previous GPS trace I’ll fetch that trace into the editor. It’s my GPS trace so all of the data (waypoints and all) are available to me, even though it is not visible as a GPS trace to anyone else.
Sometimes, I might want to make a trace public, perhaps to link to as an example of something. These tend to be ones not in an out of my front door 