Codename: Kids Next Door Season 4 Episode 9

Operation: K.N.O.T. is a Numbuh 1 episode.
Operation: C.L.O.S.E.T. is a team episode.

This marks the second time an adult wants to help one of the Kids Next Door since Operation C.O.W.G.I.R.L..

Numbuhs 3 and 5 do not appear in "Operation K.N.O.T." It was the second time since "Operation L.U.N.C.H."

The operative that had the clipboard in C.L.O.S.E.T had hair like Yugi's on Yu-Gi-Oh.

When the KND roll out of the closet, two operatives are shown playing in the bedroom as they wait and a toy dog is shown, also. The toy strangely resembles "Spike," the dog from the Nickelodeon show, Rugrats.

This is the first instance of Nigel truly befriending an adult (other than his father).

Sector V must be somewhat of celebrities among the KND - the other operatives in "C.L.O.S.E.T." seemed excited to see them.

"K.N.O.T." stands for Kids Necks Overwhelmingly Tied; "C.L.O.S.E.T." stands for Child Lost On Seriously Elevated Tundra.

Judging by what Moosk says, "K.N.O.T." takes place on a Tuesday.

Credits: Billy and the snow suit are on a rollar coaster, at a baseball game, in front of Romance Burger, playing Ding-Dong Ditch, watching a movie, playing in the park, and then his mom washes the suit and the suit shrinks so when Billy takes the suit out and notices it, he starts crying.

This marks the first appearance of Numbuh 1's mother.