Presentation for PIDapalooza 2016. PIDs need to be used to achieve their intended persistence. Our research (reported at WWW2016, see http://arxiv.org/1602.09102) found that a disturbing percentage of references to papers that have DOIs actually use the landing page HTTP URI instead of the DOI HTTP URI. The problem is likely related to tools used for collecting references such as bookmarks and reference managers. These select the landing page URI instead of the DOI URI because the former is what's available in the address bar. It can safely be assumed that the same problem exists for other types of PIDs. The net result is that the true potential of PIDs is not realized. In order to ameliorate this problem we propose a Signposting pattern for PIDs (http://signposting.org/identifier/). It consists of adding a Link header to HTTP HEAD/GET responses for all resources identified by a DOI, including the landing page and content resources such as "the PDF" and "the dataset". The Link header contains a link, which points with the "identifier" relation type to the DOI HTTP URI. When such a link is available, tools can automatically discover and use the DOI URI instead of the other URIs (landing page, PDF, dataset) associated with the DOI-identified object.