In terms of resolving this issue, is this something that we can adjust in the Texinfo output settings?  If not, can we change the octave.css file to get the right result?  Last shot might be to define a new macro @xresult which is decoded to " @result{}" for HTML formats and "@result{}" for all others.

The Texinfo character that results from @result{} is "=>" in a plaintext environment (2 characters) but just 1 character (&Rarr) in HTML.  This throws the alignment of columns off.  Here is one example from the documentation from cstrcat: file:Rarr_example.png.

And here is how the documentation appears in a plaintext environment:

          s = [ "ab"; "cde" ];
          cstrcat (s, s, s)
                => "ab ab ab "
                   "cdecdecde"