Hi Long,
I had forgotten that MB can do that, so thanks for pointing it out! However, what I think would be nice is a solution that is a bit more complete.
Because phone numbers around the world have different formatting systems, it would be really nice to have a field that is more flexible. That is why I propose a field that has a built-in drop-down for selecting the proper country code. Once the user has selected the code for their country, the form could automatically use the proper format validation for that country’s phone number format.
Is this something that could be done?