[Definition:] An entity reference refers to the content of a named entity.
[Definition:] References to parsed general entities use ampersand (&) and semicolon ( ;) as delimiters.
[Definition:] Parameter-entity references use percent-sign (%) and semicolon ( ;) as delimiters.
If the keyword of the conditional section is a parameter-entity reference, the parameter entity must be replaced by its content before the processor decides whether to include or ignore the conditional section.
An example: ( from W3C XML Spec
<!ENTITY % draft 'INCLUDE' >
<!ENTITY % final 'IGNORE' >
<![%draft;[
<!ELEMENT book (comments*, title, body, supplements?)>
]]>
<![%final;[
<!ELEMENT book (title, body, supplements?)>
]]>
This little paragraph, and the example shown, document the key trick that makes conditional sections useful. Rather than having the actual words INCLUDE or IGNORE as the keyword, normally you'd have a parameter-entity reference, so that you could, by redeclaring that entity in the internal subset, switch back and forth between conditional sections.
Clear as mud??
------------------
Ajith Kallambella M. Sun Certified Programmer for the Java�2 Platform.
[Ajith disabled smilies!]
[This message has been edited by Ajith Kallambella (edited August 06, 2001).]