In Team Fortress 2's short film 'Expiration Date', during Scout's conversation with Miss Pauling near the start of the film, a keypad can be seen on the door behind him. When examined closer, the '1' key is noticeably dented when compared to the other keys. This implies that the combination for the door is some variant of '1111' - The same combination for BLU's intelligence room in Meet the Spy.
Contributed by Edd-the-Huntsman
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