About

Punycode is a encoding that:

• converts unicode characters (ie international character)
• into the ASCII (A-Z, 0-9) character set.

Usage

• The main usage is to store international characters in a system that supports only ascii.
• Application such as web browsers use it to defend against Homograph phishing attacks.
• It's used in DNS name to support International Domain Names (IDNs).
  • in url host
  • in hostname
  • …