<!doctype html>
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/2692">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1467309">
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<link rel="author" title="Mozilla" href="https://mozilla.org">
<title>-- is a reserved property name</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
test(function() {
  assert_false(CSS.supports("--", "initial"), "-- is a reserved property name");
});
</script>