Street art
Imagery made in public space outside official channels (wheat-pastes, stencils, murals, sticker art), rooted in graffiti culture but generally aimed at the passing public rather than at other writers.
The sanctioned/unsanctioned line has blurred to near-invisibility: institutions now commission artists who built their names without permission, and "street art" as a label often signals a visual style more than a legal status. What survives of the original distinction is audience: street art talks to whoever walks by, where graffiti's lettering traditions carry a conversation between writers.
For documentation, impermanence is the defining fact. Street art is made to weather, be painted over, or disappear with the building, so the photograph and the record often outlive the work. That makes mapping and archiving this material feel less like administration and more like preservation.