Part of the story in the Abstergo offices of Assassin’s Creed IV: Black Flag is told through a series of collectible post-it notes that you find around the office. Once the game is over you can actually roam all the office locations at your leisure to pick them up, but here’s a quick guide on where and when you can find each one.
Note 4: Floor 2, left of the toilet entrance (Sequence 1)
Happy note hunting!
Update 8th Dec: I’m playing through again on PS4 (1080p, woo) so have updated all the slightly vague note locations.