@item Z
Compress the specified files (@code{dired-do-compress}). If the file
appears to be a compressed file already, uncompress it instead. Each
-marked file is compressed into its own archive. This uses the
+marked file is compressed into its own archive; this uses the
@command{gzip} program if it is available, otherwise it uses
-@command{compress}.
+@command{compress}. On a directory name, this command produces a
+compressed @file{.tar.gz} archive containing all of the directory's
+files, by running the @command{tar} command with output piped to
+@command{gzip}. To allow decompression of compressed directories,
+typing @kbd{Z} on a @file{.tar.gz} or @file{.tgz} archive file unpacks
+all the files in the archive into a directory whose name is the
+archive name with the extension removed.
@findex dired-do-compress-to
@kindex c @r{(Dired)}
\f
* Changes in Specialized Modes and Packages in Emacs 26.2
+** Dired
++++
+*** The 'Z' command on a directory name compresses all of its files.
+It produces a compressed '.tar.gz' archive with all the files in the
+directory and all of its subdirectories. For symmetry, 'Z' on a
+'.tar.gz' or a '.tgz' archive extracts all the archived files into a
+directory whose name is the archive name sans the '.tar.gz' or '.tgz'
+extension. (This change was actually made in Emacs 26.1, but was not
+called out in its NEWS.)
+
** Ibuffer
---