Notation

The act or practice of recording anything by marks, figures, or characters.

Any particular system of characters, symbols, or abbreviated expressions used in art or science, to express briefly technical facts, quantities, etc. Esp., the system of figures, letters, and signs used in arithmetic and algebra to express number, quantity, or operations.

Literal or etymological signification.

A system of symbols used to represent numbers, operations, or objects

a comment or instruction (usually added); "his notes were appended at the end of the article"; "he added a short notation to the address on the envelope"