DOCBOOK: title vs. citetitle and ulink in biblioentry

Hi.

I'm new to DocBook so was searching the archives on the best way to link to
an online article in a biblioentry. I found a message [1] by Norm Walsh that
recommends this:

<biblioentry>
  <citetitle><ulink url="...">title</ulink></citetitle>
  ...
</biblioentry>

This was a little perplexing to me since the example for bibliography [2]
uses title instead of citetitle.

Then I stumbled across another message [3] also from Norm mentioning that
allowing title in biblioentry was probably a mistake.

Using either title or citetitle with a nested ulink renders fine for me but
I was wondering what the correct element, semantically speaking, is? Should
bilbioentrie elements always use citetitle even without a nested ulink?
Should the example be updated to reflect this best practice?

Thanks,
Jason

[1]
http://lists.oasis-open.org/archives/docbook/200007/msg00121.html
[2]
http://docbook.org/tdg/en/html/bibliography.html
[3]
http://lists.oasis-open.org/archives/docbook/200107/msg00119.html