Creating reproducible tar files

[anonmous at sigaint.org]

Please change the recommendation to use --owner=0 --group=0 instead of
--owner=root --group=root as the end goal is to achieve 0 anyway and root
may not always lead to 0:

https://superuser.com/questions/877037/root-user-uid-got-changed

Similarly using --owner=root --group=root --numeric-owner with tar.exe in
windows leads to non-zero ids while --owner=0 --group=0 --numeric-owner
leads to 0 ids.

Other than that, I am not very familiar with these: --mode=go=rX,u+rw,a-s

What does it do? Could you document the benefits compared to using
--mode=644 or --mode=755

Does it guarantee reproducible results?