In a cross reference, you must always name a node. This means that in
order to refer to a whole manual, you must identify the `Top' node by
writing it as the first argument to the @xref command. (This
is different from the way you write a menu entry; see section Referring to Other Info Files.) At the same time, to
provide a meaningful section topic or title in the printed cross
reference (instead of the word `Top'), you must write an appropriate
entry for the third argument to the @xref command.
Thus, to make a cross reference to The GNU Make Manual, write:
@xref{Top, , Overview, make, The GNU Make Manual}.
which produces
*Note Overview: (make)Top.
and
See section "Overview" in The GNU Make Manual.
In this example, `Top' is the name of the first node, and `Overview' is the name of the first section of the manual.