|Out of Stargate universe information|
Colonel O'Neil (with only one "L") is a US military.
When Armin Selig, an investigation journalist, is about to make public the Stargate Program, and more, to reveal what really happened a few months ago in space (SG1: "The Serpent's Lair"), Colonel Jack O'Neill tells to him to correctly spell his last name as there is another Colonel "O'Neil" with only one "L", and this one has absolutely no sense of humour.
- It is generally accepted to say that Richard Dean Anderson (Colonel Jack O'Neill's portrayer) was making a hint to the "Jonathan “Jack” O'Neill"'s character portrayed by Kurt Russell in the Stargate original movie, a much more serious character than the one portrayed by Anderson.
- O'Neil's nationality is deducted as he's part of the US military.