| Extension | File Description |
| .LIBRARIES | Uncommon Files |
| .LIBRARY | Uncommon Files |
| .library-ms | System Files |
| .LIBS | Uncommon Files |
| .LIC | Misc Files |
| .LICENSE | Uncommon Files |
| .LICK4 | Uncommon Files |
| .LID | Misc Files |
| .LIE | Uncommon Files |
| .LIF | Data Files |
| .LIFE | Data Files |
| .LIG | Uncommon Files |
| .LIGH | Uncommon Files |
| .LIGHT | Uncommon Files |
| .LIGHTNING | Uncommon Files |
| .LIH | Uncommon Files |
| .LII | Uncommon Files |
| .LIJ | Uncommon Files |
| .LIK | Uncommon Files |
| .LIL | Uncommon Files |
| .LILLIES | Uncommon Files |
| .LIM | Uncommon Files |
| .LIN | CAD Files |
| .LINDBERG | Uncommon Files |
| .LINEEDIT | Uncommon Files |
| .LINES | Uncommon Files |
| .LINK | Misc Files |
| .LINK66 | GIS Files |
| .LINKTP | Uncommon Files |
| .LINO | Uncommon Files |
| .LINUX | Uncommon Files |
| .LIO | Uncommon Files |
| .LIP | Game Files |
| .LIQ | Uncommon Files |
| .LIQCRYS | Uncommon Files |
| .LIR | Uncommon Files |
| .LIS | Text Files |
| .lisp | Developer Files |
| .LISPM | Uncommon Files |
| .LIST | Developer Files |
| .LIST3820 | Settings Files |
| .LISTAFP | Settings Files |
| .LISTER | Uncommon Files |
| .LISTING | Uncommon Files |
| .LISTLAYOUT | Uncommon Files |
| .LISTS | Uncommon Files |
| .LISTTHEME | Uncommon Files |
| .LIT | Text Files |
| .LIU | Uncommon Files |
| .LIV | Uncommon Files |
| .LIVEREG | Data Files |
| .LIVESUBSCR | Uncommon Files |
| .LIVEUPDATE | Data Files |
| .LIW | Uncommon Files |
| .LIX | Data Files |
| .LIY | Uncommon Files |
| .LIZ | Uncommon Files |
| .LI_ | Uncommon Files |
| .LJ | Uncommon Files |
| .LJ0 | Uncommon Files |
| .LJ1 | Uncommon Files |
| .LJ2 | Uncommon Files |
| .LJ3 | Uncommon Files |
| .LJ4 | Uncommon Files |
| .LJ5 | Uncommon Files |
| .LJ6 | Uncommon Files |
| .LJ7 | Uncommon Files |
| .LJ8 | Uncommon Files |
| .LJ9 | Uncommon Files |
| .LJA | Uncommon Files |
| .LJB | Uncommon Files |
| .LJBDOWNLOA | Uncommon Files |
| .LJC | Uncommon Files |
| .LJD | Uncommon Files |
| .LJE | Uncommon Files |
| Extension | File Description |
| .LJF | Uncommon Files |
| .LJG | Uncommon Files |
| .LJH | Uncommon Files |
| .LJI | Uncommon Files |
| .LJJ | Uncommon Files |
| .LJK | Uncommon Files |
| .LJL | Uncommon Files |
| .LJM | Uncommon Files |
| .LJN | Uncommon Files |
| .LJO | Uncommon Files |
| .LJP | Uncommon Files |
| .LJQ | Uncommon Files |
| .LJR | Uncommon Files |
| .LJS | Uncommon Files |
| .LJT | Uncommon Files |
| .LJU | Uncommon Files |
| .LJV | Uncommon Files |
| .LJW | Uncommon Files |
| .LJX | Uncommon Files |
| .LJY | Uncommon Files |
| .LJZ | Uncommon Files |
| .LK | Uncommon Files |
| .LK0 | Uncommon Files |
| .LK1 | Uncommon Files |
| .LK2 | Uncommon Files |
| .LK3 | Uncommon Files |
| .LK4 | Uncommon Files |
| .LK5 | Uncommon Files |
| .LK6 | Uncommon Files |
| .LK7 | Uncommon Files |
| .LK8 | Uncommon Files |
| .LK9 | Uncommon Files |
| .LKA | Uncommon Files |
| .LKB | Uncommon Files |
| .LKC | Uncommon Files |
| .LKD | Uncommon Files |
| .LKE | Uncommon Files |
| .LKF | Uncommon Files |
| .LKG | Uncommon Files |
| .LKH | Uncommon Files |
| .LKI | Uncommon Files |
| .LKJ | Uncommon Files |
| .LKK | Uncommon Files |
| .LKL | Uncommon Files |
| .LKM | Uncommon Files |
| .LKN | Uncommon Files |
| .LKO | Uncommon Files |
| .LKP | Uncommon Files |
| .LKQ | Uncommon Files |
| .LKR | Uncommon Files |
| .LKS | Uncommon Files |
| .LKT | Uncommon Files |
| .LKU | Uncommon Files |
| .LKV | Uncommon Files |
| .LKW | Uncommon Files |
| .LKX | Uncommon Files |
| .LKY | Uncommon Files |
| .LKZ | Uncommon Files |
| .LL | Game Files |
| .LL0 | Uncommon Files |
| .LL1 | Uncommon Files |
| .LL2 | Uncommon Files |
| .LL3 | Uncommon Files |
| .LL4 | Uncommon Files |
| .LL5 | Uncommon Files |
| .LL6 | Uncommon Files |
| .LL7 | Uncommon Files |
| .LL8 | Uncommon Files |
| .LL9 | Uncommon Files |
| .LLA | Uncommon Files |
| .LLB | Data Files |
| .LLC | Uncommon Files |
| .LLD | Uncommon Files |
| .LLE | Uncommon Files |
| .LLF | Uncommon Files |
