Preventing Reader from creating hyperlinks

I am trying to prevent Acrobat Reader from interpreting an XML namespace as a URL that is hyperlinked. My namespaces have http://* in the names, but do not resolve to web pages, since they are only namespaces. I have tried inserting zero-width spaces to no avail, as well as a number of other characters to try to prevent Reader from picking these up as URLs. Any ideas on how to prevent my customer's versions of Reader from automatically converting URL-looking text to links?