Ok I did miss something
I was taking things too literally and assuming that we were talking about numbers as actually used in TG. After all your TGDs are just scripts (Open one in a text editor), accessed through a convenient user interface.
In theory it should be possible to write an entire planet using nothing more complex than Notepad.
I have never come across a scripting language that accepts anything other than the full stop as the decimal point; the separator for lists of numbers / parameters varies but is most commonly the comma (TGD appears to relay on simple spacing).
The ability to accept regional variations would greatly complicate the process of generating / interpreting scripts, either the editor would have to translate to and from a common format or the script would need to contain some kind of region identification so the editor knew how to interpret it. The second option could prove complicated if a script written in one region was to be modified by someone in a different region. This would suggest that the adoption of a single standard would simplify things. No doubt I will be shown loads of examples to the contrary but from what I have seen the standard is as I previously stated.
I didn't choose it: Queen Victoria is alive and well and working at the checkout next to Elvis and half the world is still pink.
HTML drives me nuts making me leave the U out of colour and spelling centre center WRONG.
POV-Ray accepts colour with or without the U (U is included for the Canadians)?
I imagine that accents or other "Extended character sets" will always cause problems as there is littler or no standardisation in which or how they are used..
Arabic: No offence, I know that it predates all our "Western languages" but it's just squiggles to me
