*In earlier seasons, the knife is generally called Ruby's Knife by the characters. Its referred to as just the Demon-Killing Knife by [[Mary Winchester]] in [[14.01 Stranger in a Strange Land]].
*Though the knife played a role as the Winchesters main demon-killing weapon in the earlier seasons, it has lost its prevalence in the later seasons, particularly after the revelation that [[angel blade]]s can also kill demons. In the later seasons, the Winchesters use angel blades to kill demons more often the knife which then typically only appears once or twice a season.
*Before Sam uses the knife to kill [[Kipling]] in [[14.01 Stranger in a Strange Land]], the last time either of the Winchesters used it to kill a demon was in [[12.12 Stuck in the Middle (With You)]] when Sam killed the male demon protecting [[Ramiel]].