The latest version of an answer (that I created and Community last edited) is not displaying or editing right. Instead, a version that still has a dead URL in it* is displayed both on the main page for the Q, and when I try to edit that latest version of my A.
*I think it's the next-to-latest version, which was by me, of 25 May, with https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man8/fsck_hfs.8.html still in it.
It looks like the dead URL is removed per that screen shot above.
But here below we see the dead URL is still linked to: (Screen shot from How to check whether there is bad sector on an external USB hard disk on OS X?)