[Amadou]

There is some other system that uses periods for thousands and commas for decimals - the exact reverse of what you've listed as the english convention. I always thought it was a european convention. It makes more sense than what you've listed as the metric convention.

[fastball]

Indeed, and that is what I've seen from many Europeans.

However, I think that must be a convention from before the universal adoption of the metric system by the EU, as the 22nd General Conference on Weights and Measures (held in 2003) declared that the symbol for decimals should be "the point on the line or the comma on the line".

i.e. the official metric system symbol is period or comma, regardless of what actual Europeans use.

http://www.bipm.org/utils/en/pdf/Resol22CGPM-EN.pdf [page 11]

[coldtea]

>i.e. the official metric system symbol is period or comma, regardless of what actual Europeans use.

Regardless? Those (and mainly comma) is exactly what Europeans use. It's not like there is some other symbol besides those too in use for that purpose.

[fastball]

Yes, there is another convention. (spaces)+(commas or periods) != (periods)+(commas)

What you are talking about is a European convention, not a metric convention. There is a difference.

[siddboots]

Esperanto and Interlingua both use that convention.