Apologies, should this already have been discussed.
http://meta.wikimedia.org/wiki/Wikidata/Notes/Data_model#The_Metamodel defines: Wikipedialink = (Title, LanguageId, Badge?)
In my experience the scope or extent of entities in different Wikipedias sometimes differs. One Wikipedia considers an entity a valid lemma, whereas another Wikipedia subsumes it in a larger lemma.
Would changing the model to: Wikipedialink = (Title, LanguageId, Relation, Badge?) where relation can be broader match close match exact match narrower match
etc. help in expressing these situations? I believe this could prevent problems later on.
The default (and initial import of interlanguage links) could easily be "close match" - to be refined only where required.
Gregor