Watchmen
From Tardis Wiki, the free Doctor Who reference
Watchmen was a DC Comics series with the Smiley Face as a famous icon.[source needed]
Ace had a pin of the Watchmen Smiley Face on her black bomber jacket. (TV: Remembrance of the Daleks, The Power of the Doctor)
The Seventh Doctor had a pin of the Watchmen Smiley Face with his suit of cream linen during an adventure in the System. (PROSE: Sky Pirates!)