The Reserve Collection contains books that are in high demand for teaching, reading groups, etc. They have a shorter borrowing period than open shelf books so that as many people can access them as possible. They are distinguished in iDiscover by the note:
Whipple Library: Reserve Collection (ask at Staff desk)
Books on Reserve can be borrowed at any time, and will be due back by closing time the next day (or Monday, if borrowed on Friday). You will still need to check out out the book if you are only using it in the library (i.e. not taking it away).
Books on Reserve are not available for vacation loan.