Here's a potential problem. I added the following DNIDs to these Wikipedia pages:
numismatics.org:1858.1.1 to Half cent coin (United States coin).
numismatics.org:1952.81.2 to Sestertius.
numismatics.org:2006.21.9 to Sestertius.
numismatics.org:1975.134.7 to Sestertius.
Now, Wikiepedia thinks numismatics.org is a source of wiki-spam and Google is following that lead. You can see this at http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Spam/LinkReports/numismatics.org. Also, a Google search for numismatics.org lists that wiki spam report pretty high. What's worse, this google search produces no useful results. It used to list this blog post, which mentioned numismatics.org:1949.100.10.
Probable lesson: don't link DNIDs to original data on Wikipedia or you risk raising the domain's "spammer quotient."