.METADATA_NEVER_INDEX File Extension

Hidden file created on hard drives, flash drives, iPods, and other volumes used with Mac OS X; named ".metadata_never_index" and is typically located in the root directory, or top level of a disk.

The metadata_never_index file prevents Spotlight, Apple's built-in search tool, from indexing a directory or an entire volume. It is a blank file that is not meant to be opened by the user. Removing the file may allow the folder or volume to be indexed by Spotlight on Mac OS X systems.