Nathank started out talking about the mouseover text, but I took it a bit further. One of his ideas was having it display the name of the setting selection, like “Normal”, rather than the name of the “Tracking” feature – because, as Moin said,
Right now “tracking” is used as the name for a notification level within the dropdown and as a term for the feature to choose a notification level.
I suggested tweaking the names of the settings systemwide, so a.) they’d generally be more understandable, and b.) we’d no longer have to realize my Tracking setting is… Tracking. In my example sets, that choice would be named Track or Tracked – just different enough to be clear.
(Whether the mouseover used setting names, or your good suggestion "Set your notification level for this topic”, it would improve the situation nathank brought up.)