PHP 4.2.2 - direct relay into expat 1.9.5
Processing instructions according to the W3C workgroup
do not form part of the character stream, but are
supposed to be passed directly to the application. As
such, they should be allowed to appear anywhere.
xml and Xml as targets are reserved. The targets can
make use of a Notation in the dtd to clarify the
application to receive the processing instruction.
Expat as constructed does not allow for processing
instructions to appear anywhere arbitrarily but requires
that they appear outside tags. However, the W3C
mandate clearly indicates that <TAG attribute="<?target
something?>"/> is a valid construct.
In attempting to make use of this construct, expat
repeatedly stopped with an invalid response.
Also, it was not clear whether the processing instruction
was expected to return a value that would instead be