I can’t seem to submit an idea so I would just like to put out there that I’m going to have to build a regex because the Canadian zip code validation is set to be case sensitive. Respondents who are typing fast or do not want to stop to format may be bounced from a true answer and told to retype which might introduce confusion if the zip code is technically correct, just not formatted as expected.
Alternative2: Slack verification has a one character per box format and automatically upper-cases the letters. This would be a good format to replicate for countries that have alphanumeric zip codes where formats (dash or no dash? space or no space, uppercase or lowercase, consistent or inconsistent) are more varied than the American digits-only format.