Ha! That’ll teach me to not read around the subject! Marc has already written about the problems peopleaggregator has been having in picking up who is the main “Person” in a FOAF file. Of course, I already provide dc:creator and foaf:maker properties to associate my “Person” with the FOAF document, so there shouldn’t be any problem, but as Morten and Libby point out in the comments I should also be using foaf:topic (I didn’t think this had been decided on as a method of specifying the author of an FOAF file, but there you go).

From what Marc says it looks like they’re not parsing the FOAF files with an RDF parser, but some kind of scraper to get the information out; they were looking for the first foaf:name element in the file and finding the main “Person” that way. Apart from using dc:creator, foaf:maker or foaf:topic inside the <rdf:Description rdf:about=""> element, they could use an algorithm similar to Morten’s Topic Finder which is A web service for guesstimating the primary FoaF “thing” described in an RDF/XML file.