xml-dev - Unnecessary well-formedness constraint

[Elliotte Rusty Harold <elharo@metalab.unc.edu>]

Section 4-1 of the XML 1.0 second edition spec states:


Well-Formedness Constraint: In DTD
Parameter-entity references may only appear in the DTD.  


The Annotated XML spec notes that:

This constraint is not actually wrong, but it is rather misleading.
Suppose I have a parameter entity named Fred, then if the string %Fred;
appears somewhere in the document, outside of the DTD, that's not an
error as this suggests; it's just the string %Fred;.

So my question is why is this constraint here at all? What is its
effect? If we removed it form the spec (say in the third edition) would
this in any way change which document are considered to be well-formed
or valid? Would removing it give parsers any leeway they don't have now?
Right now this seems like an unnecessary statement to me. 

-- 
+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
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|               Java I/O (O'Reilly & Associates, 1999)               |
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