[Serialization] XHTML (sic) Output Method

In the Serialization paper reference is made, for example, in the header to 
Chapter 5 to the "XHTML" (sic) output method.

I suggest that the chapter header be expressed as "The xhtml Output Method" 
to avoid unnecessary ambiguity.

Similar comments apply to other headers where incorrect case is used e.g. 
HTML (sic) Output Method.

The same problem also occurs in the text - for example in the third Note in 
5. reference is made to the XHTML (sic) output method.

Andrew Watt