\nnn may refer to:
- \nnn (octal), representation of literals (such as characters) as octal numbers (common)
- \nnn (decimal), representation of characters as decimal numbers (rare)
- TIO code, trigraph representation of characters as decimal numbers in Hewlett-Packard palmtops
See also
edit- \n
- nnn (disambiguation)
- \xnn (hexadecimal)