Punycode encoding/decoding

1. Punycode is an encoding system primarily used to convert domain names from Unicode format to ASCII.

2. Punycode-encoded strings contain only ASCII characters, ensuring compatibility with existing systems.

3. Punycode encoding is reversible, meaning a Punycode-encoded string can be decoded back to its original non-ASCII string.

4. Security was considered in the design of Punycode to prevent certain types of encoding attacks.

5. Since the Domain Name System (DNS) only supports ASCII characters during resolution, Punycode encoding was developed.