This structure is used by the dictionary-list to inform
its listeners about certain events.
Since the dictionary-list is able to collect several single
events before broadcasting them to it's listeners the
integer argument may be a combination (logical or) of several
event types.
If more specific information about the events is requested by a
listener, a sequence of all dictionary-list events since the
last broadcasting will be supplied. Otherwise, that list will
be empty.
