notation

英[nəʊ'teɪʃ(ə)n] 美[no'teʃən]

1. a technical system of symbols used to represent special things

2. 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"

3. the activity of representing something by a special system of marks or characters