https://docs.python.org/3/library/multiprocessing.html#address-formats currently states

> An 'AF_PIPE' address is a string of the form r'\.\pipe{PipeName}'. To use Client() to connect to a named pipe on a remote computer called ServerName one should use an address of the form r'\ServerName\pipe{PipeName}' instead.

which suggests that if the pipe is named "foo", the string should be r'\.\pipe{foo}' (especially given that the other substituted string, ServerName, is given in italics... but actually the correct format is r'\.\pipe\foo'.

Hence I would suggest fixing the markup to give name formats as r'\.pipe\PipeName' where PipeName, is in italics, like ServerName.

There's a formatting problem in Doc/library/multiprocessing.rst due to consumption of the backslashes in multiple steps. The following keeps all of the required backslashes in the HTML output:

    * An ``'AF_PIPE'`` address is a string of the form
      :samp:`r'\\\\\\.\\pipe\\\\{PipeName}'`.  To use :func:`Client` to connect to a named
      pipe on a remote computer called *ServerName* one should use an address of the
      form :samp:`r'\\\\\\\\{ServerName}\\pipe\\\\{PipeName}'` instead.

Or just use a regular literal and rely on the reader to understand that "{PipeName}" and "{ServerName}" are parameters:

    * An ``'AF_PIPE'`` address is a string of the form
      ``r'\\.\pipe\{PipeName}'``.  To use :func:`Client` to connect to a named
      pipe on a remote computer called *ServerName* one should use an address of the
      form ``r'\\{ServerName}\pipe\{PipeName}'`` instead.