Ampersand connector in XML

Tim Bray tbray at
Tue Mar 30 04:32:48 BST 1999

At 12:24 PM 3/30/99 +1000, Alison Lennon wrote:
>Could someone please explain to me why the ampersand group connector
>of SGML was not included in XML. 
>It seems to me that the absence of this connector results in
>significant problems for many applications based on XML that want to
>use unordered lists of elements.

Simply because it's a lot harder to implement than all the other
content model apparatus.  In fact, back in SGML days, it was well-known
to be buggy in several rather good and successful SGML products.  Yes,
its absence does represent a loss in expressive power.  At the time,
it seemed like a good trade-off.  To me it still does, although it
has particularly irked the (large and growing number of) people who
want to use XML to model relational semantics. -Tim

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