Template: panden-sorteren.php — available attributes
$sort — Sorting the visitor chose last, e.g. koopPrijs-asc; empty for the default sorting.
$options — Sort options as value => label, starting with '' => 'Standaard'.
$action — URL the form posts to (shortcode attribute action); empty means the current page.
$label — Label above the select (shortcode attribute label); empty hides it.
$hiddenFilters — Filters the visitor already set, as name => value; sent along as hidden inputs so sorting keeps them.
The select must be named pandSorteer, the rw_panden shortcode sorts on that field.