Problem with ls man page

[Cappellini, Tony]

Hello,

The man page for the ls command displays the following  option
--sort=WORD
              extension -X, none -U, size -S, time -t, version -v

However, when I type ls --sort- -X, to sort by extension, ls displays the
following error message

ls: invalid argument `-X' for `--sort'
Valid arguments are:
  - `none'
  - `time'
  - `size'
  - `extension'
  - `version'
Try `ls --help' for more information.

When I type ls --sort=extension, the current directory is sorted by the file
extension, which is what I want.

The man page is listing the wrong information for this option.

thanks

Tony