v+
$ man k3b
[...]
--cdimage
Write an ISO image or Bin/Cue image to cd
[...]
$ k3b --cdimage
k3b: Unknown option 'cdimage'.
k3b: Use --help to get a list of available command line options.
$ k3b --help
[...]
--image <url> Write an image to a CD or DVD
[...]
v-
I think that explains everything. Man for k3b should be updated to
reflect actual state of supported options.
There is another outdated option in the man page. The man page says to use --datacd to burn a data cd, however when you run k3b --help it states that the correct option is --data. k3b --help is correct that --data is used to burn a data cd.