Google requires at least two ListItem entries. In a typical URL-based implementation, provide position, name, and item for each entry. The final entry may omit item, in which case Google uses the current page URL. URLs for intermediate entries are not universally optional.
In January 2025, Google announced the removal of breadcrumbs from mobile search results. Desktop results continue to support them. Adding valid markup does not guarantee its appearance in search or an increase in click-through rate.