+\f
+version 1.21.90 (CVS)
+
+* Support for xz compression
+
+Tar uses xz for compression if at least one of the following
+conditions is met:
+
+ 1. The option --xz or -J (see below) is used.
+ 2. The xz binary is set as compressor using --use-compress-program option.
+ 3. The file name of the archive being created ends in `.xz' and
+ auto-compress option (-a) is used.
+
+Xz is used for decompression if at least one of the following
+conditions is met:
+
+ 1. The option --xz or -J is used.
+ 2. The xz binary is set as compressor using --use-compress-program option.
+ 3. The file is recognized as xz compressed stream data.
+
+* Short option -J
+
+The decision to assign -J option was taken just before the XZ format
+has been officially declared stable. Now, that stable xz tools are
+available, the -J option is re-assigned as a short equivalent of --xz.
+
+* New option -I
+
+The -I option is assigned as a short equivalent for
+--use-compress-program.
+