| q | Q Engine Data |
| q00 | Intuit Quicken 2000 Data |
| q01 | Intuit Quicken 2001 Data |
| q06 | Intuit QuickTax 2006 Tax Return Data |
| q07 | Intuit QuickTax 2007 Tax Return Data |
| q08 | Intuit QuickTax 2008 Tax Return Data |
| q09 | Intuit QuickTax 2009 Tax Return Data |
| q1p | Yamaha QY100 Style Data |
| q2d | Quick 3D Cover Design |
| q3x | QuickDraw 3D Extension |
| q43 | Aqbanking Q43 Data |
| q4w | Qualitek-4 Exported Data |
| q98 | Intuit Quicken 98 Data |
| qa | GPS Quality Assessment Data |
| qaa | WinQSB Data File |
| qabs | QuickShow Shape Data |
| qag | Norton Desktop Quick Access Group Data |
| qam | Omnis Quartz Audio |
| qar | QlikView Extension |
| qassoc | PLINK Quantitative Trait Association Test Report Data |
| qat | Microsoft Office Quick Access Toolbar Data |
| qax | Quanquest Axes Definition Data |
| qb | Diploma Question Bank File |
| qb | Qubicle Binary Data |
| qb1 | Quicken Deluxe Backup |
| qbd | SQL Navigator Query Builder Data |
| qbem | QuickShow Beam Sequence Data |
| qbi | Intuit QuickBooks Image file |
| qbj | Intuit QuickBooks Journal Data |
| qbk | Intuit QuickTax 2009 Backup |
| qbl | Intuit QuickBooks License File |
| qbmb | QuickBooks Backup |
| qbmd | Intuit QuickBooks for Mac Backup Data |
| qbo | Intuit QuickBooks Online Bank Statement |
| qbp | Intuit QuickBooks Print File |
