There doesn't seem to be a distribution zip file ?
The example page doesn't show the N/A variants.
No mention of -1 and -26 exceptional fine / bad
BTW - your other post which mentioned meteometrics Zambretti page. It looks like they've reworded their working description after 'we' proved they got it wrong https://cumulus.hosiene.co.uk/viewtopic.p ... ti&start=0