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Currently there are two different coding standards: GRIB edition 1 (commonly referred to as GRIB1) and GRIB edition 2 (GRIB2). The major differences are in the structure of the messages; in GRIB2, several variables are defined with more precision (e.g. in GRIB1, latitudes and longitudes are in milli-degrees while in GRIB2, they are in micro-degrees). Also in GRIB2, longitude values must lie between 0 and 360 degrees), the encoding of the parameter is very different, and in GRIB2 the description of the data is template/table based. Note that a GRIB file can contain a mix of GRIB1 and GRIB2 messages.
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