| ins | Sample Cell II Instrument Definition |
| instr | Magix Music Studio VST Instruments Data |
| ircam | IRCAM SoundFile |
| isma | IIS Smooth Streaming Audio |
| ist | Digitrakker Instrument Data |
| it | Impulse Tracker Music Module |
| iti | Impulse Tracker Instrument |
| its | Impulse Tracker Music Sample |
| itz | Impulse Tracker Music Module |
| ivc | InterVoice Audio Data |
| j6s | Ricoh Digital Camera Sound |
| jat | JUCE Audio Thumbnail Data |
| jbm | JBM Adlib Music Data |
| jcb | JCB-JCBrooke Music Module |
| jge | Roland Juno-G JGE Data |
| jgl | Roland Juno-G JGL Library |
| jo | JO Audio File |
| jo-7z | jo Audio |
| joy | Trackjoy GUS Tracker Song |
| jwf | Buzz Jacinth Waveform Audio |
| jwl | Buzz Jacinth Waveform Library |
| jxx | Yamaha SY77 Audio Data |
| k25 | Kurzweil K2500 Data |
| k26 | Kurzweil K2600 Data |
| ka1 | Kawai K5000 Patch |
| kaa | Kawai K5000 Patch |
| kam | Meragana Karaoke Data |
| kar | MIDI Karaoke Song |
| kat | Katorzer Music Composition |
| kdt | Konami KDT1 Song |
| keyboard | Amaya Keyboard Configuration Data |
| kfn | KaraFun Karaoke File |
| kft | Korg T1 Wave Data |
| ki | Klystrack Instrument |
| kit | NI Battery Drum Kit |
| kls | Kenwood HD60GD9 Lossless Audio |
| kmp | Korg Trinity Keymap |
| kmp3 | TKaraoke Karaoke MP3 Audio |
| koala | Koala Sampler Song |
| korg | Korg Trinity Sample |
| koz | Audiokoz Music |
| Sprint Music Store Music Data |
| kr1 | Kurzweil K2000 Split Data |
| kr2 | Kurzweil K2000 Split Data |
| kr3 | Kurzweil K2000 Split Data |
| kraw | BRSTM Audio Stream |
| kris | Kris Tracker Format Song |
| krk | Xbox Music Mixer Karaoke-enabled Music |
| krz | Kurzweil K2000 Data |
| ksc | Korg Trinity Script |
| ksd | NI Kore Sound |
| ksds | NI Absynth Kore Patch Format Sound |
| ksf | Korg Trinity Sample |
| ksm | Kefrens-Sound Machine Audio |
| Ken Silverman Music |
| kss | MSX KSS Audio Data |
| kt | Klystrack Music |
| kt2 | NI Battery 2 Drum Kit |
| kt3 | NI Battery 3 Drum Kit |
| kts | KT-Tech Compressed Audio |
| kws | Kyocera Phone Ringtone |
| kxs | Kexis Lossless Compressed Audio |
| kxsfc | kX Project SoundFont Collection Data |
| l | Sound Designer 2 Left Channel Data |
| la | Lossless Audio Compressed Data |
| laa | LucasArts AdLib Audio |
| latm | AAC Low Overhead Audio Transport Multiplex |
| lb | Low Bitrate Packer Compressed Audio |
| lds | Loudness Sound System Audio |
| liq | Liquid Tracker Song |
| liw | Cakewalk Music Creator Chord Library |
| lme | LegglessMusicEditor Music Module |
| lmsff | Liquid Audio Player Audio |
| loas | AAC Low Overhead Audio Stream |
| lpc | LPC-10 Encoded Audio |
| lpc10 | LPC-10 Encoded Audio |
| lpcm | Linear Pulse Code Modulated Audio |
| lqt | Liquid Audio Player Data |
| lrc | Lyrics Data |
| lrec | Inter-Tel Web Conferencing Recording |
