In a theatre, the prompt corner or prompt box is the place where the prompter—usually the stage manager in the US or deputy stage manager in the UK—stands in order to coordinate the performance and to remind performers of their lines when required.
Historically, the prompt corner was situated at stage left.
[1] However some theatres choose to install prompt corner in a discreet area of the auditorium.
This can vary from a small table in the wings to an elaborate installation in a dedicated booth, being equipped with all the necessary aids for the specific production and venue.
The prompt desk minimally holds a carefully annotated copy of the performance script, with blocking and other stage directions and, in professional theatres: