Two files in the same directory with the exact same name?! #

What's up with this?

Let's find out. ls | od -a reveals:

Doh! Missed that space after the filename extension. (Thanks to Edgar Holmann & Tom Ivar Helbekkmo who posted to this thread back in 1990.)

Updates

See also Zhitao Zhou's Can we believe our eyes? which examines two "hosts" files in %SystemRoot%\system32\drivers\etc caused by malware replacing "o" (Unicode 0x006F) with a nearly identical Cyrillic character (Unicode 0x043E).
Delete a directory with a trailing space in its name
These files both seemingly have the same filename and, though lacking file extensions, are identified in the "Kind" column as Word documents (DOC and DOCX, respectively):

Is there some kind of metadata/extended attribute magic going on here to allow this? Nope - just that darn trailing space again:
grep not returning text known to be in file

/nix | Jul 14, 2006