rec-csymbol1

W3C sample	WIRIS
	$J_{0} y$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <csymbol encoding="OpenMath" definitionURL="http://www.openmath.org/cd/BesselFunctions.ocd">
      <msub>
        <mi>J</mi>
        <mn>0</mn>
      </msub>
    </csymbol>
    <ci>y</ci>
  </apply>
</math>

Author: MathML 2 Recomendation