+ Some compression programs are able to handle different compression
+formats. GNU `tar' uses this, if the principal decompressor for the
+given format is not available. For example, if `compress' is not
+installed, `tar' will try to use `gzip'. As of version 1.25 the
+following alternatives are tried(2):
+
+Format Main decompressor Alternatives
+---------------------------------------------------------------------
+compress compress gzip
+lzma lzma xz
+bzip2 bzip2 lbzip2
+