from Marcus Carr:
>You have received some very good advice about how to represent occurrences of
>elements with and without data, but there is another factor that may help you
>produce "good, well structured files". You may want to consider if the element
>need exist at all, if it has no contents (or attributes). If you can, make the
>element optional in the structure - it's much tidier than leaving in tags that
>don't contribute meaningfully to the structure of the document.
i agree that one should streamline their data and structures; however, sometimes elements can have optional data. for example, i maintain a simple address book in XML and some of the elements remain empty because i do not have data for that element (my dad's fax number, for example, because he doesn't have a fax). so at times the elements have data, sometimes they don't.