Hi @roadmr,
The tracks indicate the version of the Ubuntu series in which they will be installed.
This is in the same lines as [1,2,3]. There is a nice discussion on the reasoning for these track names in [3].
Note that, after [4], we did have an offline discussion on the future of these tracks, as mentioned by @sergiodj in [4], and we will push to stop requesting these in the future. However, we will still most likely file a new request for 22.04 tracks for all these snaps in the near future so we can follow the same standard for the 22.04 OCIs until a new solution is in place.
[1] Request for new tracks for loki snap [2] Cassandra 21.10 track request [3] New tracks for prometheus and prometheus-alertmanager snaps [4] Request for new tracks for loki snap