🔁 ROT13 Cipher
ROT13, ROT5, ROT18, ROT47 — apply twice = original (self-inverse cipher).
Standard. Encode = decode (apply twice = original).
Output
💡 Fun fact:
ROT13 is a Caesar cipher with shift 13. Since the alphabet has 26 letters, applying ROT13 twice returns the original. Used historically in Usenet to hide spoilers.