I've seen a few situations where the different ways to write numbers with more than three digits has become a small topic of discussion itself within comments.
One case is the use of a period versus a comma as a demarkation between the whole number and decimals. For example pi could be written either as 3.142 or 3,142 depending on where in the world the author has studied.
Similarly, An Astronomical Unit is exactly 149597870700 meters. I'd write that as 149,597,870,700 meters, but it's written in Wikipedia as
using thin spaces in lieu of comma delimiters.
What are all of the acceptable ways to do this here, and if possible what might a good set of personal options be for me to adopt to be the most user-friendly to the widest variety of international readers here?