Document the new BUFFER arg to the `shell' command.

etc/NEWS

@@ -965,6 +965,13 @@ the face used for each string/comment.
 *** A new standard face `font-lock-doc-face'.
 Meant for Lisp docstrings, Javadoc comments and other "documentation in code".
 
+** Changes to Shell mode
+
+*** The `shell' command now accepts an optional argument to specify the buffer
+to use, which defaults to "*shell*".  When used interactively, a
+non-default buffer may be specified by giving the `shell' command a
+prefix argument (causing it to prompt for the buffer name).
+
 ** Comint (subshell) changes
 
 These changes generally affect all modes derived from comint mode, which

man/misc.texi

 @c This is part of the Emacs manual.
-@c Copyright (C) 1985, 86, 87, 93, 94, 95, 97, 2000
+@c Copyright (C) 1985, 86, 87, 93, 94, 95, 97, 2000, 2001
 @c   Free Software Foundation, Inc.
 @c See file emacs.texi for copying conditions.
 @iftex
@@ -443,11 +443,10 @@ for time to elapse.
 face @code{comint-highlight-prompt}.  This makes it easier to see
 previous input lines in the buffer.  @xref{Faces}.
 
-  To make multiple subshells, rename the buffer @samp{*shell*} to
-something different using @kbd{M-x rename-uniquely}.  Then type @kbd{M-x
-shell} again to create a new buffer @samp{*shell*} with its own
-subshell.  If you rename this buffer as well, you can create a third
-one, and so on.  All the subshells run independently and in parallel.
+  To make multiple subshells invoke @kbd{M-x shell} with a prefix
+argument (e.g. @kbd{C-u M-x shell}), which will cause it to prompt for
+a buffer name, and create (or reuse) a subshell in that buffer.  All
+subshells in different buffers run independently and in parallel.
 
 @vindex explicit-shell-file-name
 @cindex @env{ESHELL} environment variable