I did a search for "jumbo chunk" and while I got results, none of them actually had the word "jumbo".

We should probably have a note somewhere in the docs that explain what jumbo chunks are, maybe on this page:
http://docs.mongodb.org/manual/tutorial/modify-chunk-size-in-sharded-cluster/ ?

It doesn't need to be emphasized or anything, but we also shouldn't have it completely missing from our docs.