A stub signal left behind in an
old format for users who have yet to convert to the new format. The term comes from the SAFER Act, a US law allowing analog TV stations to keep broadcasting information on digital conversion (and, in some cases,
local news and emergency information) after the station has otherwise
gone all-digital.
I tried running some old
Mac software on an old
Mac, but forgot the software I was using was PowerPC-only. Good thing the nightlight
box popped up; now I have to go find my PowerBook G3.