by adding a list of the form @samp{("/dev/name" @var{function} @var{mode})} to
@code{eshell-virtual-targets}. The first element is the device name;
@var{function} may be either a lambda or a function name. If
-@var{mode} is nil, then the function is the output function; if it is
-non-nil, then the function is passed the redirection mode as a
+@var{mode} is @code{nil}, then the function is the output function; if it is
+non-@code{nil}, then the function is passed the redirection mode as a
symbol--@code{overwrite} for @code{>}, @code{append} for @code{>>}, or
@code{insert} for @code{>>>}--and the function is expected to return
the output function.