Line notation is a typographical notation system using ASCII characters, most often used for chemical nomenclature.

Chemistry

• Cell notation for representation of an electrochemical cell
• Dyson / IUPAC (1944)
• Hayward (1961)
• International Chemical Identifier (InChI)
• Wiswesser Line Notation (WLN) (1952)
• Simplified molecular input line entry specification (SMILES)
• Smiles arbitrary target specification (SMARTS)
• SYBYL Line Notation (SLN)

Mathematics

• Mathematical markup language

Music

• GUIDO music notation

Chess

• Forsyth–Edwards Notation