OSF-ICZ-OriSAFE
OSF-Opera-skin-file
OSF-Virtual-Ticket-file
OSG-OpenSceneGraph-ASCII-Native-Format-OSG-Community
OSI-Osiris-Database-The-Shmoo-Group
OSI-SunNet-OSI-Description-File-Sun
OSL-OckamSoft-Log-File-Ockam-Instruments-Inc
OSM-OpenStreetMap-XML-Data-Header
OSP-CWCDATA-file
OSP-Obi-Synth-Pack-Music-Header
OSP-On-Screen-Takeoff-file
O-Sprint-Outfile
OSS-Search-file-Microsoft-Office
OST-Offline-file-Microsoft-Exchange-Outlook
OSX-OSW-external-file
OSZ-OSU-Beatmap-File-Zipped
OTAN-Mac-File-Type
OT-Atari-Jaguar-TOM-object-code
OTB-Nokia-OTA-bitmap-file
OTB-Nokia-Over-The-Air-Bitmap
OTB-On-the-air-Bitmap
OTC-OpenDocument-Chart-Template
OTC-OpenDocument-chart-template-file
OTF-Blu-ray-Text-Subtitle-Font-Information-Blu-ray-Disc-Association
OTF-OnkoS-Text-Data-File
OTF-OpenDocument-Formula-Template
OTF-OpenOffice-StarOffice-OpenDocument-Ver-2-Formula-Template-Sun-Microsystems-Inc
OTF-OpenTuft-Tufting-Design-File
OTF-OpenType-Font
OTF-OpenType-font-file-format
OTGL-Mac-File-Type
OTG-OpenDocument-Graphic-Template
OTHERFOLDER-Power-Toys-Other-Folder-Explorer-Tool
OTH-Microsoft-PowerToys-Explorer-tool
OTH-OpenDocument-HTML-document-template-OpenOffice-org
OTH-OpenOffice-org-OpenDocument-HTML-text-template
OTH-Origin-Graph-Properties-File-OriginLab-Corporation
OTH-Power-Toys-Other-Folder-Explorer-Tool
OTI-OpenDocument-Image-Template
OTLN-Opal-Outline-File
OTL-Outline-font-description-Z-Soft-Type-Foundry
OTL-Template-file-PrintMaster-Gold
OTL-Template-file-Super-NoteTab-Fookes
OTM-Micro-Cookbook-File-IMSI-Design-LLC
OTM-Outlook-Macro-File
OTM-Unknown-Apple-II-File
OTNC-Mac-File-Type
OTN-OmniPage-Training-File-Nuance-Communications-Inc
OTO-Autopano-Project-Alexandre-Jenny
OTOSET-OTOsuite-Settings-GN-Otometrics
TechTarget file types