'status' label for Cox & Fell data

Good day, for the Cox & Fell (2020) Sleep Medicine Reviews edf files, it contains a lot of EEG data and in the end, I think in the 59th label, there exists the "status" label with the unique values of 0, 1, 2, and 3. Could someone please help me to identify what these numbers indicate or mean?

Thanks in advance, aztecbinaynay

I pinged the creator of this Luna vignette with your question - https://zzz.bwh.harvard.edu/luna/vignettes/rcox/ (in the vignette the Status column is ignored)