Document protocols supported by URL library via Tramp

* doc/misc/url.texi (Tramp): New node, describes the URL schemes
supported via Tramp.
(Supported URL Types, file/ftp, rlogin/telnet/tn3270): Mention
Tramp.

doc/misc/url.texi

@@ -373,9 +373,10 @@ for specific schemes.
 * rlogin/telnet/tn3270::        Remote host connectivity.
 * irc::                         Internet Relay Chat.
 * data::                        Embedded data URLs.
-* nfs::                         Networked File System
-* ldap::                        Lightweight Directory Access Protocol
+* nfs::                         Networked File System.
+* ldap::                        Lightweight Directory Access Protocol.
 * man::                         Unix man pages.
+* Tramp::                       Schemes supported via Tramp.
 @end menu
 
 @node http/https
@@ -549,8 +550,8 @@ file://@var{user}:@var{password}@@@var{host}:@var{port}/@var{file}
 @noindent
 If the URL specifies a local file, it is retrieved by reading the file
 contents in the usual way.  If it specifies a remote file, it is
-retrieved using the Ange-FTP package.  @xref{Remote Files,,, emacs,
-The GNU Emacs Manual}.
+retrieved using either the Tramp or the Ange-FTP package.
+@xref{Remote Files,,, emacs, The GNU Emacs Manual}.
 
   When retrieving a compressed file, it is automatically uncompressed
 if it has the file suffix @file{.z}, @file{.gz}, @file{.Z},
@@ -682,7 +683,8 @@ telnet://@var{user}:@var{password}@@@var{host}:@var{port}
 @end example
 
 @noindent
-but the @var{password} component is ignored.
+but the @var{password} component is ignored.  By default, the
+@code{telnet} scheme is handled via Tramp (@pxref{Tramp}).
 
 To handle rlogin, telnet and tn3270 URLs, a @code{rlogin},
 @code{telnet} or @code{tn3270} (the program names and arguments are
@@ -798,6 +800,38 @@ The @code{man} scheme is a non-standard one.  Such URLs have the form
 and are retrieved by passing @var{page-spec} to the Lisp function
 @code{man}.
 
+@node Tramp
+@section URL Types Supported via Tramp
+
+@vindex url-tramp-protocols
+Some additional URL types are supported by passing them to Tramp
+(@pxref{Top, The Tramp Manual,, tramp, The Tramp Manual}).  These
+protocols are listed in the @code{url-tramp-protocols} variable, which
+you can customize.  The default value includes the following
+protocols:
+
+@table @code
+@item ftp
+The file transfer protocol.  @xref{file/ftp}.
+
+@item ssh
+@cindex ssh
+The secure shell protocol.  @xref{Inline Methods,,, tramp, The Tramp
+Manual}.
+
+@item scp
+@cindex scp
+The secure file copy protocol.  @xref{External Methods,,, tramp, The
+Tramp Manual}.
+
+@item rsync
+@cindex rsync
+The remote sync protocol.
+
+@item telnet
+The telnet protocol.
+@end table
+
 @node General Facilities
 @chapter General Facilities
 

etc/NEWS

@@ -758,6 +758,7 @@ See the doc string of `sh-indent-after-continuation' for details.
 
 ** URL
 
++++
 *** The URL package accepts now the protocols "ssh", "scp" and "rsync".
 When `url-handler-mode' is enabled, file operations for these
 protocols as well as for "telnet" and "ftp" are passed to Tramp.