+ The default is to include all available types of data. The
+ option can be specified multiple times to select some subset. As
+ of version 2 of the dump format, there is a header line of the
+ following form
+
+ |
+ | #notmuch-dump <*format*>:<*version*> <*included*>
+
+ where <*included*> is a comma separated list of the above
+ options.