Direct links from the knowledge base are specifically crafted by the WorldCat Knowledge Base team and vendors to consistently resolve to where the user needs to go. The A-Z linker, however, which Tipasa also uses, only takes the information available and then searches for a match in the knowledge base. In the case of Tipasa, it is using the metadata provided in the request. This is why a link may appear in the A-Z list or Tipasa without linking correctly: the system has found a match, but the vendor platform in question may have a method of linking that is not sufficient for reaching a resource.