| Abbreviation | Definition |
|---|---|
| LCH | IBM Works for OS/2 Chart file |
| LCK | Lock file (especially for database access control) |
| LCL | FTP Software PC/TCP Local Data |
| LCN | Lection (WordPerfect) |
| LCS | ACT! History File Datafile |
| LCW | Spreadsheet (Lucid 3-D) |
| LCX | LC Export File format |
| LD | Long Distance codes file (Telix) |
| LD1 | Overlay file (dBASE) |
| LDB | Data filer database (IBM Works for OS/2) |
| LDB | Record-locking information (MS Access) |
| LDF | Geoworks Library Definition File |
| LDF | IBM Works for OS/2 Data Filer Form |
| LE | Executable image (DOS/4GW PM 32X DOS Extender) |
| LEF | Library Exchange Format |
| LEG | Document (Legacy) |
| LES | Computer-based training LESson file |
| LESS | LEaner cSS |
| LEV | NetHack 3.x Level file |
| LEX | Lexicon (dictionary) (many) |