If you see a book in InfoHawk+ that includes the word FOLIO in the call number, this means the book is larger than normal and therefore doesn't fit well on our regular shelves. We have oversize/folio shelves against the walls on the outer edges of the floors that house our collections in the Main Library.
Example:

Here's a guide to where to find the oversize/folio books:
fA - fD |
5th Floor, east |
fE - fF435 |
5th Floor, west |
fF437 - fKBP422 |
4th Floor, east |
fKBP494.4 - fZ |
4th Floor, west |