Although the easiest way to use the register is to report all the
postings affecting a set of accounts, it can often result in more
information than you want.  To cope with an ever-growing amount of
data, there are several options which can help you pinpoint your
report to epostly the postings that interest you most.  This is
called the ``calculation'' phase of Ledger.  All of its related
options are documented under @option{--help-calc}.