shortname=lower|win95|winnt|mixed
Defines the behaviour for creation and display of filenames which fit into 8.3 characters. If a long name for a file exists, it will always be
preferred display. There are four modes: :
lower Force the short name to lower case upon display; store a long name when the short name is not all upper case. This mode is the default.
win95 Force the short name to upper case upon display; store a long name when the short name is not all upper case.
winnt Display the shortname as is; store a long name when the short name is not all lower case or all upper case.
mixed Display the short name as is; store a long name when the short name is not all upper case.