minuscules vs lieux inférieurs

The toLocaleLowerCase() method returns the value of the string converted to 
lower case according to any locale-specific case mappings. 
toLocaleLowerCase() does not affect the value of the string itself. 
In most cases, this will produce the same result as toLowerCase(), 
but for some locales, such as Turkish, whose case mappings do not follow the 
default case mappings in Unicode, there may be a different result.
Glamorous Goshawk