@node Reproducibility
@section Making @command{tar} Archives More Reproducible
-Sometimes it is important for an archive to be reproducible,
-so that one can be easily verify it to have been derived solely from its input.
+Sometimes it is important for an archive to be @dfn{reproducible},
+so that one can be easily verify it to have been derived solely from
+its input. We call an archive reproducible, if an archive
+created from the same set of input files with the same command line
+options is byte-to-byte equivalent to the original one.
+
However, two archives created by @GNUTAR{} from two sets of input
files normally might differ even if the input files have the same
contents and @GNUTAR{} was invoked the same way on both sets of input.