What does the dashed line under status numbers in vocabulary mean?

I see in my vocabulary list on the site that sometimes a status number is highlighted yellow, sometimes it is highlighted yellow with a dashed line underneath, and sometimes there’s only a dashed line. What do these mean?

The dashed line is under the 4, right? It means it’s a known LingQ (beyond 4). I haven’t seen highlighted and a dashed line.

Status 1 words have a dark yellow highlight, Status 2 are lighter yellow, Status 3 are light yellow with a dashed line underneath and Status 4 have no highlight with a dashed line underneath. Known words have no highlight and no dashed line.