Ftp, an old protocol, seems to be blessed by numerous implementations.
Unfortunately, some implementations are noisy (ie., add junk to the end of the
file).  Thus, concerned users may decide to write a NetReadFixup() function
that will clean up after reading with their ftp.  Some Unix systems (ie.,
FreeBSD) provide a utility called "fetch" which uses the ftp protocol but is
not noisy and more convenient, actually, for <netrw.vim> to use.
Consequently, if "fetch" is available (ie. executable), it may be preferable
to use it for ftp://... based transfers.

For rcp, scp, sftp, and http, one may use network-oriented file transfers
transparently; ie.
>
	vim rcp://[user@]machine/path
	vim scp://[user@]machine/path
<
If your ftp supports <.netrc>, then it too can be transparently used
if the needed triad of machine name, user id, and password are present in
that file.  Your ftp must be able to use the <.netrc> file on its own, however.
>
	vim ftp://[user@]machine[[:#]portnumber]/path
<
Windows provides an ftp (typically c:\Windows\System32\ftp.exe) which uses
an option, -s:filename (filename can and probably should be a full path)
which contains ftp commands which will be automatically run whenever ftp
starts.  You may use this feature to enter a user and password for one site: >
	userid
	password
<				*netrw-windows-netrc*  *netrw-windows-s*
If |g:netrw_ftp_cmd| contains -s:[path/]MACHINE, then (on Windows machines
only) netrw will substitute the current machine name requested for ftp
connections for MACHINE.  Hence one can have multiple machine.ftp files
containing login and password for ftp.  Example: >

    let g:netrw_ftp_cmd= 'c:\Windows\System32\ftp -s:C:\Users\Myself\MACHINE'
    vim ftp://myhost.somewhere.net/

will use a file >

	C:\Users\Myself\myhost.ftp
<
Often, ftp will need to query the user for the userid and password.
The latter will be done "silently"; ie. asterisks will show up instead of
the actually-typed-in password.  Netrw will retain the userid and password
for subsequent read/writes from the most recent transfer so subsequent
transfers (read/write) to or from that machine will take place without
additional prompting.

								*netrw-urls*
  +=================================+============================+============+
  |  Reading                        | Writing                    |  Uses      |
  +=================================+============================+============+
  | DAV:                            |                            |            |
  |  dav://host/path                |                            | cadaver    |
  |  :Nread dav://host/path         | :Nwrite dav://host/path    | cadaver    |
  +---------------------------------+----------------------------+------------+
  | DAV + SSL:                      |                            |            |
  |  davs://host/path               |                            | cadaver    |
  |  :Nread davs://host/path        | :Nwrite davs://host/path   | cadaver    |
  +---------------------------------+----------------------------+------------+
  | FETCH:                          |                            |            |
  |  fetch://[user@]host/path       |                            |            |
  |  fetch://[user@]host:http/path  |  Not Available             | fetch      |
  |  :Nread fetch://[user@]host/path|                            |            |
  +---------------------------------+----------------------------+------------+
  | FILE:                           |                            |            |
  |  file:///*                      | file:///*                  |            |
  |  file://localhost/*             | file://localhost/*         |            |
  +---------------------------------+----------------------------+------------+
  | FTP:          (*3)              |              (*3)          |            |
  |  ftp://[user@]host/path         | ftp://[user@]host/path     | ftp  (*2)  |
  |  :Nread ftp://host/path         | :Nwrite