Change to tarball generation?

[Allen Winter]

On Wednesday 23 May 2012 1:28:04 PM Wulf C. Krueger wrote:
> Hello Albert et al,
> 
> On 23.05.2012 18:58, Albert Astals Cid wrote:
> > The machine i'm generating the tarballs doesn't have pixz so i'll
> > use xz.
> 
> Even though it's somewhat coincidental ;): Thank you.
> 
> Personally, I think it would be an excellent idea to stick to the
> standard xz format until the non-standard extensions that were used
> for the last batch of tarballs get standardised themselves.
> 
> (Those extensions caused user-visible breakage at least on Exherbo
> Linux and Gentoo Linux.)
> 

This whole thread is confusing me.

Maybe a command line would help?

Is this correct?
% tar cvf kdefoo-x.y.z.tar <files>
% xz kdefoo-xy.z.tar
=> resulting in kdefoo-x.y.z.tar.xz

if not, please tell us what a command line should be

I take it from mpyne's original posting that:
% tar Jcvf kdefoo-x.y.z.tar.xz <files>
isn't the way to go??