There is a reference to a "small grammatical error" in the rejection from Harvard, but I did not quite understand what he was referring to. Was that obvious fr

There is a reference to a "small grammatical error" in the rejection from Harvard, but I did not quite understand what he was referring to. Was that obvious from his reply and I missed the point? I am guessing it must be in the form of "Please accept our letter of rejection" or similar?