[Zope] Zope powered Sites on Zope.org code

Hello, on zope.org the list of Zope powered sites is automatically compiled from all links with the keyword "Powered by Zope". On zope.se I would like to include a similar feature, but I can not filter links on the keywords. Do I have to change the catalog or what else is it I miss? Maybe the code from Zope.org is available? TIA Ulrich -- World Wide Web Publisher, Ulrich Wisser, Vallatorpsv.158, S-18752 Täby http://www.publisher.de Tel: +46-8-53460905 Fax: +46-8-534 609 06