Answered By: Library Reviewer Last Updated: Oct 16, 2014 Views: 66
Those abbreviations refer to the different stack levels and sub levels of the Library:
SL1 = Stack Level 1
LL1 = Lower Level 1
SL2 = Stack Level 2
SL3 = Stack Level 3
LL2 = Lower Level 2
For more information about the layout of the Library and for maps, see page 22 and following in our Law Library Guide here.