Note: "FALL ARREST".
I beleive it is over 10 (ten) feet. Before fall Arrest comes into play. I'll have to check.
But I do know (after being cited),that near an opening, elev pit,stairwell etc. You must be at least as far away as the ladder is tall,or be tied off.
EX: 6' ladder- six feet away-8'-10' etc. if closer, you need to be tied off.
10' for me and a $225 fine.(contractor paid, My as- chewed)
"Sorry, Dude".