I've noticed this a few times, and it continues to puzzle me, so I'll share it with you, dear reader, via the gift of the mobile phone camera and the internet.

What could possibly be "notional" about a corridor? Is it really a corridor? In fact, the switch may operate lights within a room, or it may operate the lights of the stairwell. I don't know. What does this switch operate? The label isn't saying. Perhaps it relates to a string of lights that could be used to form a corridor of light across the open plan office space in which we are resident? Perhaps not. The label ain't saying. My opinion is this. If the description's no good, don't bother with it. Also, if it needs too much explaining, it's also probably wrong.

There. I've gotten that off my chest.