Defenders are allowed to ask each other whether they have cards in the suit in Zone 2 and Zone 7. So it is a Zonal habit rather than a regional one.
Where are Zone 2 and Zone 7? Zone 2 is North America, basically the USA, Canada, Mexico and Bermuda. Zone 7 is Australasia, basically Australia and New Zealand.
Note this is an example of why we always ask people to put their country when asking questions: there are so many distinctions based on geography in the rules of bridge.
If you are curious as to which countries are in which Zone then take a look at
Zonal Organisations and National Bridge Organisations