vior will be
  important to you if you use one of those packages.  In particular,
  <a class="xref" href="libpq-envars.html" title="34.15. Environment Variables">Section 34.15</a>,
  <a class="xref" href="libpq-pgpass.html" title="34.16. The Password File">Section 34.16</a> and
  <a class="xref" href="libpq-ssl.html" title="34.19. SSL Support">Section 34.19</a>
  describe behavior that is visible to the user of any application
  that uses <span class="application">libpq</span>.
 </p><p>
  Some short p