mongodb/docs — pull request #185 by aheckmann (2012-09-05 17:43:37+00:00)
Title: clarify $elemMatch projection example

see http://stackoverflow.com/questions/12274957/does-elemmatch-not-work-with-a-new-mongodb-2-2/12286852#12286852
and https://github.com/learnboost/mongoose/issues/1085