Little tags like these are mounted in Japanese hotels rooms – in room corners, behind the doors or on the ceilings.

What are they? What is their purpose?

My limited deciphering tells me these tags have something to do with the fire department, and they are a form of “definitive identification” useful during the course of disasters.

Like the fire hydrants in Perth, these identity tags are part of the unspoken, taken-for-granted systems and processes that are known within a society but remain completely opaque to visitors.