can I do this in windows?

Firstly, thank you for interesting in this thread

Well, some peoples maybe agree if they do website development in Linux version and I too, but I do not have ipv6 right now
 
in case if I use 

Code:

lang('lower.DisplayMe')

in windows, it's okay. But it will throw an error in Linux, so I must use Upper string, isn't?

But, can Windows do same way as Linux did? I mean, if  I use lower string in lang function, it will throw an error in Windows.

note : I forget what is the name of this behavior. Thank you.