;Registration statement : This initializes the report by a single call to the <tt>register()</tt> function. It is trivial, but without it your report will not become available to Gramps, even if it is otherwise perfectly written.
A report can potentially be generated as a standalone report, as a Gramps Book item, and as a command line report. The registration determines which modes are enabled for a given report. The report class does not have to know anything about the mode. The options class is there to provide options interface for all available modes.