Wall Graffiti are small Easter Eggs found in the game Mirror's Edge. They are almost always found on walls or on the floor next to the Runner bags. Some contain cryptic, sometimes useless clues, though others reveal a slight part of the storyline.
Examples include Tic-tac-toe games or simple drawings.
In the Shard, there is a wall that has "Where is November???" spraypainted on it. Walking along the vent a little more, to where the runner bag normally is, may trigger a monologue from Faith that says "I was too young to remember exactly how it started. The authorities said the changes were for the greater good. But good isn't the same as right."