there are a handful more of these characters described later).  The
   succeeding characters up to the tab form a user display string to be
   shown to the user for use in selecting this document (or directory)
   for retrieval.  The first character of the line is really defining
   the type of item described on this line. In nearly every case, the
   Gopher client software will give the users some sort of idea about
   what type of item this is (by displaying an icon, a short text tag,
   or the like).

   The characters following the tab, up to the next tab form a selector
   string that the client software must send to the server to retrieve
   the document (or directory listing).  The selector string should mean
   nothing to the client software; it should never be modified by the
   client.  In practice, the selector string is often a pathname or
   other file selector used by the server to locate the item desired.
   The next two tab delimited fields denote the domain-name of the host
   that has this document (or directory), and the port at which to
   connect.  If there are yet other tab delimited fields, the basic
   Gopher client should ignore them.  A CR LF denotes the end of the
   item.






 
RFC 1436                         Gopher                       March 1993


   In the example, line 1 describes a document the user will see as
   "About internet Gopher".  To retrieve this document, the client
   software must send the retrieval string: "Stuff:About us" to
   rawBits.micro.umn.edu at port 70.  If the client does this, the
   server will respond with the contents of the document, terminated by
   a period on a line by itself.  A client might present the user with a
   view of the world something like the following list of items:


      About Internet Gopher
      Around the University of Minnesota...
      Microcomputer News & Prices...
      Courses, Schedules, Calendars...
      Student-Staff Directories...
      Departmental Publications...



   In this case, directories are displayed with an ellipsis and files
   are displayed without any.  However, depending on the platform the
   client is written for and the author's taste, item types could be
   denoted by other text tags or by icons.  For example, the UNIX
   curses-based client displays directories with a slash (/) following
   the name; Macintosh clients display directories alongside an icon of
   a folder.

   The user does not know or care that the items up for selection may
   reside on many different machines anywhere on the Internet.

   Suppose the user selects the line "Microcomputer News & Prices...".
   This appears to be a directory, and so the user expects to see
   contents of the directory upon request that it be fetched.  The
   following lines illustrate the ensuing client-server interaction:


    Client:           (Connects to pserver.bookstore.umn.edu at port 70)
    Server:           (Accepts connection but says nothing)
    Client: Prices/   (Sends the magic string terminated by CRLF)
    Server:           (Sends a series of lines, each ending with CR LF)
    0About PricesFPrices/AboutusFpserver.bookstore.umn.eduF70
    0Macintosh PricesFPrices/MacFpserver.bookstore.umn.eduF70
    0IBM PricesFPrices/IckFpserver.bookstore.umn.eduF70
    0Printer & Peripheral PricesFPrices/PPPFpserver.bookstore.umn.eduF70
                      (.....etc.....)
    .                 (Period on a line by itself)
                      (Server closes connection)






 
RFC 1436                         Gopher                       March 1993


3. More details

3.1  Locating services

   Documents (or other services that may be viewed ultimately as
   documents, such as a student-staff phonebook) are linked to the
   machine they are on by the trio of selector string, machine domain-
   name, and IP port.  It is assumed that there will be one well-known
   top-level or root server for an institution or campus.  The
   information on this server may be duplicated by one or more other
   servers to avoid a single point of failure and to spread the load
   over several servers.  Departments that wish to put up their own
   departmental servers need to register the machine name and port with
   the administrators of the top-level Gopher server, much the same way