special collection
library or library unit that houses materials requiring specialized security and user services or whose relation (period, subject, etc.) is to be preserved
en-US/ˈspɛʃəl kəˈlɛkʃən/
en-GB/ˈspɛʃl kəˈlɛkʃn/
library or library unit that houses materials requiring specialized security and user services or whose relation (period, subject, etc.) is to be preserved