Page 13 - D. Raleigh "Knots and ropes for climbers"

Overhand Follow-Through.

Single Fisherman's Knot.

Single Fisherman's

This knot two Overhands laced through each other is too likely to loosen and untie itself to be sound.
Don't use it. This bastardization of the Double Fisherman's is shown here only because a well-versed
climber should know which knots to avoid as well as which to use.

Common Use
None