Turnaway

The night show then pulled a turnaway and the extra night show drew near-capacity.

If only one person at a time is permitted to use an e-book (SUPO option), then users will experience "turnaways" when they try to access a title already in use. […] Presenting an option to email the library can provide a means to gather feedback from your users each time they experience a turnaway. Ask your vendor what options are available to ameliorate turnaways if that is a concern for your library.