Beside a door, above a floor, in a lobby. The same layout in each place, dressed in that building's brand, saying only what the people passing need to know.
A panel beside the door reads busy or free from the room's calendar and nothing else. No matter name, no counterparty, no partner's diary on a wall that visitors walk past.
Three rooms, the weather, the time. Nobody opens a calendar to find a free room; they look up. The theme is the studio's, applied in the admin in an afternoon.
The board cannot show who is booked into a room, because it never asks. Busy or free, and a line of guidance, is all a waiting area needs, and all a data protection officer has to sign off.
The same board runs a statement slide, the world clocks and the company calendar in turn. Change the welcome from a laptop before a visitor arrives; it is on the wall in seconds.
Every colour clears 4.5 to 1 and every state is written in words, not carried by colour. The WCAG 2.2 AA audit is published per release, and the board runs on hardware the estates team already knows.
The appliance goes behind the screen, the installer opens the admin on a laptop, applies the client's theme and checks the contrast reading. No account to create, nothing to leave running in the cloud.