List in alphabetic order - Y
- Y Yacc Source Format
- Y01 Corel Paradox Secondary Index
- Y02 Corel Paradox Secondary Index
- Y03 Corel Paradox Secondary Index
- Y04 Corel Paradox Secondary Index
- Y05 Corel Paradox Secondary Index
- Y06 Corel Paradox Secondary Index
- Y07 Corel Paradox Secondary Index
- Y08 Corel Paradox Secondary Index
- Y09 Corel Paradox Secondary Index
- Y3A Yu-Gi-Oh! ONLINE 3 Avatar Format
- Y3D Yu-Gi-Oh! ONLINE 3 Deck Format
- Y3P Yu-Gi-Oh! Online Profile
- Y3T Yu-Gi-Oh! Online Tag
- Y4M YUV4MPEG2 Video Format
- Y8PD Password Finder Yahoo! Mail / Yahoo! Messenger Exported Password
- YAB Yabasic Source Code
- YADPCM Raw Yamaha 4-bit ADPCM Format
- YAH HeartBeat
- YAJL YAJL Script
- YAK KayakFoundry 3D Design
- YAL Arts & Letters Clipart Library
- YAM Yahoo! Auctions Data
- YAML YAML Document
- YAODL PowerFlip 3D Image Format
- YAR StarBoard Document
- YAST YaST
- YAWS Yaws Source
- YBC SUSE Linux Enterprise Server Display Settings
- YBD YobiDrive Link Format
- YBHTM YBook HTML
- YBK YanCEyWare EBook
- YBM Ad-Aware 2007
- YBRAR Ybook Ebook
- YBRTF Ybook Ebook
- YBTXT Ybook Ebook
- YCHAT Yahoo! Messenger Chat Log
- YCM Yugioh Card Maker Format
- YCP SUSE Linux Enterprise Server Display Settings
- YCT YahELite Chat Transcript
- YDC Yu-Gi-Oh! Card Deck Format
- YDL PowerFlip YAODL 3D Image Format
- YDR Yu-Gi-Oh! Power Of Chaos Replay Format
- YDT Yu-Gi-Oh! Power Of Chaos Data Format
- YEL Yellow Color Separation
- YENC YEnc Format
- YFS YSFLIGHT Mission Format
- YG0 Corel Paradox Secondary Index
- YG1 Corel Paradox Secondary Index
- YG2 Corel Paradox Secondary Index
- YG3 Corel Paradox Secondary Index
- YG4 Corel Paradox Secondary Index
- YGF Y Graph Format
- YGN YGen
- YIF Mungyodance Game Data
- YKA Yenka Model Format
- YM Atari ST Audio Format
- YMAP MindGenius Computer Aided Thinking Format
- YMBK Xilisoft Mobile Manager Phonebook
- YMG Yahoo! Messenger Format
- YML YAML Document
- YML2 YML Script
- YMP YaST Metapackage Format
- YNC YEnc Encoded Format
- YOG Outerra Captured Video Format
- YOOKOO Yookoo Player Playlist Format
- YOS HP Photosmart Essential Thumbnail Cache
- YPC WhyPic Picture
- YPF YahELite Configuration
- YPR BYOB Project Format
- YPS Yahoo! Messenger Data Format
- YRCBKM YRC Weblink Bookmarks Archive
- YRM Red Alert 2: Yuris Revenge Multiplayer Map
- YRP YGOPro Replay
- YSE Yamaha Studio Manager Session
- YSM Yamaha Studio Manager
- YSP BYOB Sprite Format
- YSS YcySoft Screen Saver Producer
- YTF Google Picasa Font Cache
- YTI Google Picasa Plugin
- YTIF Independence Instrument
- YTR I.R.I.S. OCR Data
- YUV YUV Encoded Image Format
- YW3 YWriter 3 Project
- YW4 YWriter 4 Project
- YW5 YWriter 5 Project
- YWEMANIFEST Yahoo! Widgets Manifest
- YWL YoWindow Data
- YWP YWriter 2 Project
- YZ YAC Compressed Format
- YZ1 Yamazaki ZIPPER Format