In the Blue Skiddoo segment, Jane introduces her friend Carly as being deaf. Carly, however, can hear just fine, she just can't speak, meaning that she is mute and not deaf.
Steve: We'd better go look for some more signs. I mean clues.
Steve: I love convertibles, don't you? The wind blowing through your hair...
"Signs" is also the name of a major motion picture as well as a song by the Five Man Electrical Band.
David Burger is credited as "Duke" David Burger.
Mailtime Segment: Mailbox shows off that he has a sign: his flag. In the letter, a group of kids uses signs to say good morning to various people. But the boy says "Good morning, friends" without using sign language.