Catholic doctrine holds that the wafer has at that point been somehow converted or transformed into the "Body of Christ". The doctrine also states that there is no way to detect this change (i.e. to tell whether or not a given cracker has been "transubstantiated"), as the transformation involves a concept which they refer to as the "substance" of the wafer. This is a misleading label, as the physical properties of the cracker are not altered, and it is unclear why Catholics believe that a change has taken place as nobody has ever demonstrated that any change has actually taken place or even described what the effects of such a change might be.
The doctrine apparently leads to the conclusion that improper treatment of the cracker is somehow harmful to Jesus Christ – even when such improper treatment merely involves not eating the cracker, or even merely delaying such consumption until after returning to one's seat (see 2008 sacred wafer scandal).
Despite official doctrine, however, many Catholics believe (in accordance with common sense) that the transformation is meant to be purely metaphorical, and that improper handling of the wafer is a minor social crime (on the approximate order of littering or burping loudly in a quiet room); taking the cracker back to one's seat before eating it is a widespread practice among Catholics.
As of 2011-08-17, none of these reference works contains an article dedicated to this subject: