@subsection Ustar Archive Format
@cindex ustar archive format
-Archive format defined by @acronym{POSIX}.1-1988 specification is called
-@code{ustar}. Although it is more flexible than the V7 format, it
+The archive format defined by the @acronym{POSIX}.1-1988 specification is
+called @code{ustar}. Although it is more flexible than the V7 format, it
still has many restrictions (@pxref{Formats,ustar}, for the detailed
description of @code{ustar} format). Along with V7 format,
@code{ustar} format is a good choice for archives intended to be read
with other implementations of @command{tar}.
-To create archive in @code{ustar} format, use @option{--format=ustar}
-option in conjunction with the @option{--create} (@option{-c}).
+To create an archive in @code{ustar} format, use the @option{--format=ustar}
+option in conjunction with @option{--create} (@option{-c}).
@node gnu
@subsection @acronym{GNU} and old @GNUTAR{} format
SunOS and HP-UX @command{tar} fail to accept archives created using
@GNUTAR{} and containing non-@acronym{ASCII} file names, that
-is, file names having characters with the eight bit set, because they
+is, file names having characters with the eighth bit set, because they
use signed checksums, while @GNUTAR{} uses unsigned
checksums while creating archives, as per @acronym{POSIX} standards. On
-reading, @GNUTAR{} computes both checksums and
-accepts any. It is somewhat worrying that a lot of people may go
+reading, @GNUTAR{} computes both checksums and accepts either of them.
+It is somewhat worrying that a lot of people may go
around doing backup of their files using faulty (or at least
non-standard) software, not learning about it until it's time to
restore their missing files with an incompatible file extractor, or
vice versa.
-@GNUTAR{} computes checksums both ways, and accept
-any on read, so @acronym{GNU} tar can read Sun tapes even with their
+@GNUTAR{} computes checksums both ways, and accepts either of them
+on read, so @acronym{GNU} tar can read Sun tapes even with their
wrong checksums. @GNUTAR{} produces the standard
checksum, however, raising incompatibilities with Sun. That is to
say, @GNUTAR{} has not been modified to
started computing checksums wrongly. When they later realized their
mistake, they merely decided to stay compatible with it, and with
themselves afterwards. Presumably, but I do not really know, HP-UX
-has chosen that their @command{tar} archives to be compatible with Sun's.
+has chosen their @command{tar} archives to be compatible with Sun's.
The current standards do not favor Sun @command{tar} format. In any
case, it now falls on the shoulders of SunOS and HP-UX users to get
a @command{tar} able to read the good archives they receive.