On a flight, even if the โfasten seat belt signโ is turned off, I still keep the belt fastened.
Same thing with the face mask now.
Context: https://www.philstar.com/headlines/2022/09/12/2209193/marcos-oks-voluntary-use-masks-outdoors
(https://www.frederickcalica.com/?p=3336898)
So… voluntary