[Zope] calling dtml-var from ZwikiPage; strange syntax

[John Hunter]

If I have a Script (Python) python object with id HelloWorld in a
ZWiki web which has just one line:

        return "Hello World"

and then insert:

<dtml-var HelloWorld> 

in one of my ZWikiPage's, the output when I view the ZWikiPage is

Hello World>
           ^
           unexpected angle bracket in ZWikiPage output 
                      
If I change the ZWikiPage to just be 

<dtml-var HelloWorld
                    ^
                    no closing angle bracket

The 'Hello World' output is displayed with no improper angle bracket
when I view the ZWikiPage.

Is this a parser error or a feature.

Thanks,
John Hunter

zope 2.3.0
python 1.5.2