Cell-based structures can contain lists of FADC hits, segment hits, segment parameters, or vector hit parameters. The cell data structure consist of a cell header followed by one or more data items. The cell header is four bytes long and contains the following information.
In the last two cases of the flag, byte 0 becomes an estimate of the occupancy.
Note: At the moment only the FADC hits have BYTE cell headers. The others have four 32-bit words for the header.