What Is Punycode?
Punycode is an encoding system that converts Unicode characters (like Chinese, Arabic, or accented Latin characters) into the limited ASCII character set that the DNS system can process. It's the technical foundation that makes internationalized domain names (IDNs) work.
Punycode representations start with the prefix 'xn--' followed by an ASCII-compatible encoding of the original characters. For example, the German domain münchen.de is encoded as xn--mnchen-3ya.de. Browsers automatically convert between the display form and the Punycode form.
While Punycode is essential for IDN functionality, it has also been exploited for phishing attacks — homograph attacks use look-alike characters from different scripts to create domains that visually resemble legitimate ones (like using a Cyrillic 'a' instead of a Latin 'a').
Why This Matters for Startups
Most English-language startups won't need to work with Punycode directly. However, be aware of homograph attacks — someone could register a domain using look-alike characters that visually mimics your brand. Modern browsers have protections against this, but it's worth checking if your brand name could be spoofed using similar-looking characters from other scripts.
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