Right-click TextEdit in the Applications map Click “Show Package Contents“ Go to the “Contents” folder Open “Info.plist” (with an editor) Scroll all the way down Find </dict> </plist> Place this code right above it: <key>UTExportedTypeDeclarations</key> <array> <dict> <key>UTTypeConformsTo</key> <array> <string>public.text</string> <string>public.plain-text</string> </array> <key>UTTypeDescription</key> <string>NFO information file</string> <key>UTTypeIdentifier</key> <string>com.macromates.textmate</string> <key>UTTypeTagSpecification</key> <dict> <key>com.apple.ostype</key> <string>TEXT</string> <key>public.filename-extension</key> <array> <string>nfo</string> [...]