Some of Wesleyan's older collections are classified according to the Cutter Expansive Classification System. 

All numbers in the Cutter system are shelved in decimal order - F4551 comes before F46; YYD J792x comes before YYD J8d. Numbers have precedence over letters at the beginnings of lines: 9YYP before YYP before YYP9; YP83 9A7 before YP83 A7.

Many of these items are in storage, and will need to be requested through the catalog record in OneSearch. If you need assistance requesting materials, visit the Research Services office in Olin Library.