Replaces every occurrence of a link target within a single live content item, leaving the rest of the stored content untouched and publishing the change immediately. The content must be live and publicly reachable, and the new target must be an absolute http or https url, a site relative path, a mailto target or a fragment. When the current target is no longer present, because it was already replaced or never existed, the response reports NotApplied with the reason TargetNotPresent and nothing is written, so the call can safely be repeated. When the content is edited elsewhere while the replacement is being made, the response reports NotApplied with the reason ContentChanged, nothing is written and the call can be retried. The site caches content, so a change can take up to ten minutes to be visible to visitors.