KSEC1 element	Contents	GRIB octet	Recommended GRIB_API keys	Coded GRIB_API keys	Comments
37	ECMWF local GRIB use definition identifier 2 = Cluster means and standard deviations.	41	localDefinitionNumber	localDefinitionNumber
38	Class	42	class	marsClass
39	Type	43	type	marsType
40	Stream	44-45	stream	marsStream
41	Version number or experiment identifier. (4 ASCII characters, right justified)	46-49	expver	experimentVersionNumber
42	Cluster number.	50	number	clusterNumber
43	Total number of clusters.	51	totalNumberOfClusters	totalNumberOfClusters
-	Spare (set to zero)	52
44	Clustering method: 1 = Maximum linkage method 2 = Mixed method 3 = Small linkage method	53	clusteringMethod	clusteringMethod
45	Start time step considered when clustering. (Same units of time as forecast timesteps.)	54-55	startTimeStep	startTimeStep
46	End time step considered when clustering. (Same units of time as forecast timesteps.)	56-57	endTimeStep	endTimeStep
47	Northern latitude of the domain of clustering.	58-60	northernLatitudeOfDomain	northernLatitudeOfDomain	Key "domain" can be used. It contains the 4 coordinates.
48	Western longitude of the domain of clustering.	61-63	westernLongitudeOfDomain	westernLongitudeOfDomain
49	Southern latitude of the domain of clustering.	64-66	southernLatitudeOfDomain	southernLatitudeOfDomain
50	Eastern longitude of the domain of clustering.	67-69	easternLongitudeOfDomain	easternLongitudeOfDomain
51	Number of cluster to which the operational forecast belongs.	70	operationalForecastCluster	operationalForecastCluster
52	Number of cluster to which the control forecast belongs.	71	controlForecastCluster	controlForecastCluster
53	Number of forecasts belonging to the cluster, including the control forecast (N).	72	numberOfForecastsInCluster	numberOfForecastsInCluster
54-53+N	List of N ensemble forecast numbers.	73 -72+N	ensembleForecastNumbers	ensembleForecastNumbers	list of numberOfForecastsInCluster numbers
-	Spare to ensure fixed length for section.	73+N-328