Translations:Help:ExpandTemplates/42/en
$1, using $2, prevents the template $3 from expanding in the URL, and also prevents $4 from being interpreted as a separator of the parameter of urlencode from a dummy second parameter.
$1, using $2, prevents the template $3 from expanding in the URL, and also prevents $4 from being interpreted as a separator of the parameter of urlencode from a dummy second parameter.