Column number. Thousand separator should be optional.
When you use a column number to display a year, there is no need to display a thousand separator.
Yep... people still requesting this. It's such a basic function...
This has been requested for years - staggering that nothing has been forthcoming from Microsoft on this basic problem.
Star D. commented
I'm out of votes, but supporting this idea.
I also love David's comment re: leading zeros
I would expand this to include creating a new number format where you can exclude the thousand separator, and you can also specify a number of leading zeros (similar to how you can specify the number of digits displayed after the comma). Leading zeros in a field are useful in so many ways, but especially for a ZIP code field where a leading zero is valid.