Include discipline information to CodeFlag.xml

[lesserwhirls]

I would like to revisit this closed issue, as pervious versions of the XML documents had discipline information available in the Code Flag xml document. As an example, consider the code flag xml document distributed with GRIB2_22_0_0_exp.zip, which used to be obtainable from http://www.wmo.int/pages/prog/www/WMOCodes/WMO306_vI2/LatestVERSION/LatestVERSION.html (now 404s). Using the older Code Flag XML layout, we had:

<GRIB2_22_0_0_CodeFlag_exp_en>
  <No>331</No>
  <Title_en>Code table 4.1 - Parameter category by product discipline</Title_en>
  <SubTitle_en>Product discipline 0 - Meteorological products</SubTitle_en>
  <CodeFlag>0</CodeFlag>
  <MeaningParameterDescription_en>Temperature</MeaningParameterDescription_en>
  <Status>Operational</Status>
</GRIB2_22_0_0_CodeFlag_exp_en>

In the latest XML layout, the same CodeFlag entry is:

<GRIB2_CodeFlag_en>
  <Title_en>Code table 4.1 - Parameter category by product discipline</Title_en>
  <CodeFlag>0</CodeFlag>
  <MeaningParameterDescription_en>Temperature</MeaningParameterDescription_en>
  <Status>Operational</Status>
</GRIB2_CodeFlag_en>

Without the discipline information from the previously included <SubTitle_en> child, this code flag 0 cannot be distinguished from:

<GRIB2_CodeFlag_en>
  <Title_en>Code table 4.1 - Parameter category by product discipline</Title_en>
  <CodeFlag>0</CodeFlag>
  <MeaningParameterDescription_en>Hydrology basic products</MeaningParameterDescription_en>
  <Status>Operational</Status>
</GRIB2_CodeFlag_en>

[sebvi]

This is a very valid point.

I am not familiar with the xml version, we use the csv at ECMWF but do we have the same issue for the sub tables of Code Table 4.2?

[lesserwhirls]

Greetings @sebvi! The GRIB2/txt/CodeFlag.txt file still contains the discipline information for table 4.1 and 4.2 under the SubTitle_en column, which is what used to be in the xml version as <SubTitle_en> child elements.

[amilan17]

https://github.com/wmo-im/et-data/wiki/2025.04.30.et.data notes:
@antoinemerle will help with updating the scripts as needed

[amilan17]

@lesserwhirls the previous versions of GRIB and BUFR are available from this site: https://community.wmo.int/en/activity-areas/wis/previous-versions

[amilan17]

I think this change was introduced in v26, after we created a script to generate the XML in GitHub...

v25...v26

It looks like a simple fix in the py script

[amilan17]

updated the script, please review the XML in this branch

https://github.com/wmo-im/GRIB2/tree/314-include-discipline-information-to-codeflagxml

Are the empty tags ok? <SubTitle_en/>

[lesserwhirls]

Greetings @amilan17! Empty tags are ok for my use. Thank you so much!

[antoinemerle]

Thanks @amilan17 for updating the script.
So this is sorted it out ?

Thanks

[amilan17]

https://github.com/wmo-im/et-data/wiki/2025.05.27.et.data notes:
XML is updated; team noted that there no issues with integration where used;

@wmo-im/et-data can you test the XML in systems where relevant?