Sets the “INCLUDE” or “IGNORE” marked section switch for the MathML Tag Set. This switch determines whether the math processing in the MathML Tag Set %mathml.dtd; module or the %xmlspecchars.ent; module will invoke the sets of special characters that are defined AND INVOKED in the %xmlspecchars.ent; module. A value of “IGNORE” turns off the second invocation, which is located in the MathML Tag Set.