| Extension | File Description |
| .XQQ | Uncommon Files |
| .XQR | Uncommon Files |
| .XQS | Uncommon Files |
| .XQT | Executable Files |
| .XQU | Uncommon Files |
| .XQV | Uncommon Files |
| .XQW | Uncommon Files |
| .XQX | Uncommon Files |
| .XQY | Uncommon Files |
| .XQZ | Uncommon Files |
| .XR | Uncommon Files |
| .XR0 | Uncommon Files |
| .XR1 | Uncommon Files |
| .XR2 | Uncommon Files |
| .XR3 | Uncommon Files |
| .XR4 | Uncommon Files |
| .XR5 | Uncommon Files |
| .XR6 | Uncommon Files |
| .XR7 | Uncommon Files |
| .XR8 | Uncommon Files |
| .XR9 | Uncommon Files |
| .XRA | Uncommon Files |
| .XRB | Uncommon Files |
| .XRC | Uncommon Files |
| .XRD | Uncommon Files |
| .XRE | Uncommon Files |
| .XREF | Uncommon Files |
| .XRF | 3D Image Files |
| .XRG | Uncommon Files |
| .XRH | Uncommon Files |
| .XRI | Uncommon Files |
| .XRJ | Uncommon Files |
| .XRK | Uncommon Files |
| .XRL | Uncommon Files |
| .XRM | Uncommon Files |
| .XRM-MS | System Files |
| .XRN | Uncommon Files |
| .XRNS | Audio Files |
| .XRO | Uncommon Files |
| .XRP | Data Files |
| .XRQ | Uncommon Files |
| .XRR | Uncommon Files |
| .XRS | Uncommon Files |
| .XRT | Uncommon Files |
| .XRU | Uncommon Files |
| .XRV | Uncommon Files |
| .XRW | Uncommon Files |
| .XRX | Uncommon Files |
| .XRY | Uncommon Files |
| .XRZ | Uncommon Files |
| .XS | Game Files |
| .XS0 | Uncommon Files |
| .XS1 | Uncommon Files |
| .XS2 | Uncommon Files |
| .XS3 | Uncommon Files |
| .XS4 | Uncommon Files |
| .XS5 | Uncommon Files |
| .XS6 | Uncommon Files |
| .XS7 | Uncommon Files |
| .XS8 | Uncommon Files |
| .XS9 | Uncommon Files |
| .XSA | Uncommon Files |
| .XSB | Audio Files |
| .XSC | Uncommon Files |
| .XSD | Developer Files |
| .XSE | Uncommon Files |
| .XSEND | Uncommon Files |
| .XSF | 3D Image Files |
| .XSG | Uncommon Files |
| .XSH | Uncommon Files |
| .XSI | 3D Image Files |
| .XSJ | Uncommon Files |
| .XSK | Uncommon Files |
| .XSL | Data Files |
| .XSLT | Data Files |
| Extension | File Description |
| .XSM | Uncommon Files |
| .XSN | Data Files |
| .XSO | Uncommon Files |
| .XSP | Uncommon Files |
| .XSPF | Audio Files |
| .XSQ | Uncommon Files |
| .XSQL | Uncommon Files |
| .XSR | Uncommon Files |
| .XSS | Web Files |
| .XST | Settings Files |
| .XSTEP | Uncommon Files |
| .XSU | Uncommon Files |
| .XSUM | Uncommon Files |
| .XSV | Uncommon Files |
| .XSW | Uncommon Files |
| .XSWRITER | Uncommon Files |
| .XSX | Uncommon Files |
| .XSY | Uncommon Files |
| .XSZ | Uncommon Files |
| .XT | Developer Files |
| .XT* | Developer Files |
| .XT0 | Uncommon Files |
| .XT1 | Uncommon Files |
| .XT2 | Uncommon Files |
| .XT3 | Uncommon Files |
| .XT4 | Uncommon Files |
| .XT5 | Uncommon Files |
| .XT6 | Uncommon Files |
| .XT7 | Uncommon Files |
| .XT8 | Uncommon Files |
| .XT9 | Uncommon Files |
| .XTA | Uncommon Files |
| .XTB | Uncommon Files |
| .XTC | Uncommon Files |
| .XTD | Uncommon Files |
| .XTE | Uncommon Files |
| .XTEL | Uncommon Files |
| .XTF | Uncommon Files |
| .XTG | Data Files |
| .XTH | Uncommon Files |
| .XTI | Uncommon Files |
| .XTJ | Uncommon Files |
| .XTK | Uncommon Files |
| .XTL | Uncommon Files |
| .XTM | Data Files |
| .XTML | Uncommon Files |
| .XTN | Uncommon Files |
| .XTO | Uncommon Files |
| .XTODVD | Uncommon Files |
| .XTP | Data Files |
| .XTQ | Uncommon Files |
| .XTR | Uncommon Files |
| .XTS | Uncommon Files |
| .XTT | Uncommon Files |
| .XTU | Uncommon Files |
| .XTV | Uncommon Files |
| .XTW | Uncommon Files |
| .XTX | Uncommon Files |
| .XTY | Uncommon Files |
| .XTZ | Uncommon Files |
| .XU0 | Uncommon Files |
| .XU1 | Uncommon Files |
| .XU2 | Uncommon Files |
| .XU3 | Uncommon Files |
| .XU4 | Uncommon Files |
| .XU5 | Uncommon Files |
| .XU6 | Uncommon Files |
| .XU7 | Uncommon Files |
| .XU8 | Uncommon Files |
| .XU9 | Uncommon Files |
| .XUA | Uncommon Files |
| .XUB | Uncommon Files |
| .XUC | Uncommon Files |
| .XUD | Uncommon Files |
| .XUE | Uncommon Files |
