Case-Sensitivity and SVG-in-HTML

<!DOCTYPE html>
<html>
  <head>
    <style type="text/css">

svg {
  position: absolute;
}

body {
  white-space: pre;
  font: 12px Courier;
}

</style>
  </head>
  <body><script type="text/javascript">

var ns = "https://www.w3.org/2000/svg",
    svg = document.body.appendChild(document.createElementNS(ns, "svg")),
    text = svg.appendChild(document.createElementNS(ns, "textPath"));

write(document, "querySelector", "textPath"); // fail
write(document, "querySelector", "textpath"); // fail
writeAll(document, "querySelectorAll", "textPath"); // fail
writeAll(document, "querySelectorAll", "textpath"); // fail
writeAll(document, "getElementsByTagName", "textPath"); // fail
writeAll(document, "getElementsByTagName", "textpath"); // fail

write(svg, "querySelector", "textPath"); // fail
write(svg, "querySelector", "textpath"); // fail
writeAll(svg, "querySelectorAll", "textPath"); // fail
writeAll(svg, "querySelectorAll", "textpath"); // fail
writeAll(svg, "getElementsByTagName", "textPath"); // fail
writeAll(svg, "getElementsByTagName", "textpath"); // fail

write(svg, "querySelector", "*"); // success!

function write(element, method, selector) {
  var result = element[method](selector);
  document.write(element + " " + method + "(" + selector + "): ");
  if (result) document.write(result);
  document.writeln("");
}

function writeAll(element, method, selector) {
  var results = element[method](selector),
      i = -1,
      n = results.length;
  document.write(element + " " + method + "(" + selector + "): ");
  while (++i < n) {
    document.write(results[i]);
    if (i < n - 1) document.write(", ");
  }
  document.writeln("");
}

</script></body>
</html>