ROT13: Rotates letters A-Z by 13 positions. Commonly used for simple obfuscation.
ROT5: Rotates digits 0-9 by 5 positions. Useful for number obfuscation.
ROT47: Rotates ASCII 33-126 by 47 positions. Includes special characters.
Custom: Caesar cipher with any rotation (1-25). The same rotation decodes.