Required Keywords
$BEGINANALYSIS	Byte-offset to the beginning of the ANALYSIS segment.
$BEGINDATA	Byte-offset to the beginning of the DATA segment.
$BEGINSTEXT	Byte-offset to the beginning of a supplemental TEXT segment.
$BYTEORD	Byte order for data acquisition computer.
$DATATYPE	Type of data in DATA segment (ASCII, integer, floating point).
$ENDANALYSIS	Byte-offset to the end of the ANALYSIS segment.
$ENDDATA	Byte-offset to the end of the DATA segment.
$ENDSTEXT	Byte-offset to the end of a supplemental TEXT segment.
$MODE	Data mode (list mode, histogram).
$NEXTDATA	Byte offset to next data set in the file.
$PAR	Number of parameters in an event.
$PnB	Number of bits reserved for parameter number n.
$PnE	Amplification type for parameter n.
$PnR	Range for parameter number n.
$TOT	Total number of events in the data set.
Optional Keywords
$ABRT	Events lost due to data acquisition electronic coincidence.
$BTIM	Clock time at beginning of data acquisition.
$CELLS	Description of objects measured.
$COM	Comment.
$COMP	Fluorescence compensation matrix.
$CSMODE	Cell subset mode, number of subsets to which an object may belong.
$CSVBITS	Number of bits used to encode a cell subset identifier.
$CSVnFLAG	The bit set as a flag for subset n.
$CYT	Type of flow cytometer.
$CYTSN	Flow cytometer serial number.
$DATE	Date of data set acquisition.
$ETIM	Clock time at end of data acquisition.
$EXP	Name of investigator initiating the experiment.
$FIL	Name of the data file containing the data set.
$GATE	Number of gating parameters.
$GATING	Specifies region combinations used for gating.
$GnE	Amplification type for gating parameter number n.
$GnF	Optical filter used for gating parameter number n.
$GnN	Name of gating parameter number n.
$GnP	Percent of emitted light collected by gating parameter n.
$GnR	Range of gating parameter n.
$GnN	Name used for gating parameter n.
$GnT	Detector type for gating parameter n.
$GnV	Detector voltage for gating parameter n.
$INST	Institution at which data acquired.
$LOST	Number of events lost due to computer busy.
$OP	Name of flow cytometry operator.
$Pkn	Peak channel number of univariate histogram for parameter n.
$PKNn	Count in peak channel of univariate histogram for parameter n.
$PnF	Name of optical filter for parameter n.
$PnG	Amplifier gain used for acquisition of parameter n.
$PnL	Excitation wavelength for parameter n.
$PnN	Short name for parameter n.
$PnO	Excitation power for parameter n.
$PnP	Percent of emitted light collected by parameter n.
$PnS	Name used for parameter n.
$PnT	Detector type for parameter n.
$PnV	Detector voltage for parameter n.
$PROJ	Name of the experiment project.
$RnI	Gating region for parameter number n.
$RnW	Window settings for gating region n.
$SMNO	Specimen (tube or well) label.
$SRC	Source of the specimen (patient name, cell types)
$SYS	Type of computer and its operating system.
$TIMESTEP	Time step for time parameter.
$TR	Trigger parameter and its threshold.
$UNICODE	UNICODE code page for string type keyword values.