Use {{Central and South New Guinea languages |state=collapsed}} to show this template in its collapsed (hidden) state.
Use {{Central and South New Guinea languages |state=expanded}} to show this template in its expanded (fully visible) state.
Use {{Central and South New Guinea languages |state=autocollapse}} to show this template in its collapsed (hidden) state only if there is another template of the same type on the page.
Unless set otherwise (see state parameter within the template's code), autocollapse is the default state.
Template documentation