The Break header
block is an optional block found in the reports created with the report editor. It is created if a break is requested on a sort argument. The Break footer
block necessarily exists if this block exists.
This block is run whenever the value of the sort argument changes, before the first iteration of the Body block for a new value of the sort argument.
Note: The Break header and footer blocks cannot be dissociated. However, one of these blocks can be made invisible if necessary (in the description window of the block or by ..可见). See Describing the report blocks for more details.