OCSP stapling is a mechanism for checking the validity of SSL/TLS certificates — it’s also an acronym that is amongst the easiest to mix up in tech. Seriously, at some point in this explanation, you’ll likely see OCSP or some jumbled attempt at OCSP stapling, and for this I apologize and blame it on acronym-induced dyslexia. (A quick aside: Giving a group of people a name for their disorder that their disorder will make even more difficult to spell seems exceedingly cruel. I’ve never asked a dyslexic person to spell dyslexia, but I can’t imagine it going well if I did.)