Page 98 - Mario Bigon "The Morrow Guide to Knots"

running knots

Running knots, also known as slip knots or nooses, are used in
various situations, such as tying parcels or making traps and
snares. Primitive man used running knots to make weapons
and traps for capturing animals; so we can deduce that they
are among the oldest known to man. These knots are divided
into two groups, those formed by passing a bight through a
fixed loop made at the end of the rope and those made with a
closed bight knotted at the end or along the rope.
The main feature of running knots is that they tighten
around the objects on which they are made; in fact the greater
the strain on the end, the tighter the knot becomes around the
object. On the other hand, when the strain is reduced, the knot
slackens; so running knots are not used a lot in sailing.
The main running knots are the noose and the running
bowline in the first group, and the Tarbuck knot and the
hangman's knot in the second.