[atsaloli]

Yes, formally. You don't have to specify -z in GNU tar today, you can just say -x and it'll add -z or -j for you -- it figures out on the fly if the archive's been compressed and how. Very convenient.

[dminor]

You can also leave off the dash: `tar xvf`

[riquito]

And you may skip verbose too: `tar xf`