{path:item_id:relation_field}

Returns the chain of item ids from the root of a tree down to one item, as long ids joined by dashes (root first, the item itself last). It follows a relation field that points each item at its parent - the same field used to build a tree, a menu, or a Pages hierarchy. Use it for breadcrumbs and to know where an item sits in its tree. The second argument names the parent relation field and defaults to relation........ An item with no parent is its own one-element path. The id is not checked against the database: an id that matches no item is echoed straight back, and an empty first argument raises an error - always pass a real item id. See also tree, treestring, menu and sortstring, which walk the same relations.