| dgscript | DigiGuide Script |
| dgtoolbar | DigiGuide Toolbar Data |
| dgz | Dega GZipped Saved State Data |
| dhg | Direct Hit Graphics Engine Output |
| dhl | Deepnet HTTP Server Log |
| dhs | HyperSnap Captured Drawing |
| dht | GAUSS Engine Data Set Header |
| dhx | Datamine Studio Data |
| diag | Microsoft Windows Troubleshooting Pack Designer Data |
| dialog | Zoom Player Dialog Texts Data |
| dic | Microsoft Office Custom Dictionary |
| dicproof | Microsoft Word Dictionary Proofing Data |
| dict | DICT Data File |
| did | Verity Server Index Data File |
| dii | AD Summation iBlaze Data |
| dil | DesignComposer Presentation Input Script |
| dim | Direct Internet Message Encapsulation Data |
| dim | TripleSat DIMAP Data |
| dime | Direct Internet Message Encapsulation Data |
| din | WRAP DAY Input Data |
| dip | DVDINFOPro Data |
| dipx | DVDINFOPro Data |
| dis | MODFLOW Discretization Package |
| dis | MSC Patran Displacement Results |
| dis | WRAP Flow Distribution Watershed Parameters Data |
| discgrp | Geomview Discrete Groups Data |
| disp | Altair OptiStruct Displacement Data |
| dist | PLINK Genomic Hamming Distance Matrix |
| dist | SAM Scoring Data |
| dist-rdb | SAM RDB Scoring Data |
| dit | Windows 2000 Active Directory Data Store |
| dita | DITA Document |
| ditamap | DITA Topic Map |
| ditaval | DITA Conditions Data |
| dix | Apertium Monodix Dictionary Data |