Mac OS X: About Long File Names

Mac OS X uses file names up to 255 characters long. You normally see a shortened version on the desktop or in the Finder.
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Mac OS X uses file names that are up to 255 characters for files that are stored on Mac OS Extended (HFS Plus) format volumes.

A truncated version of a desktop file's long name can normally be seen. Hold the mouse pointer over a shortened file name to see the long name.

If a file with a long name is viewed while started up from Mac OS 9, some of the file name's first twenty five characters are displayed along with a unique hexadecimal reference number. To view the full file name, start up from Mac OS X.

When using a Mac OS Standard format volume, file names are limited to 31 characters.
Published Date: Oct 10, 2016