The archive format defined by the POSIX.1-1988 specification is
called ustar. Although it is more flexible than the V7 format, it
still has many restrictions (see ustar, for the detailed
description of ustar format). Along with V7 format,
ustar format is a good choice for archives intended to be read
with other implementations of tar.
To create an archive in ustar format, use the --format=ustar
option in conjunction with --create (-c).