Semiotics, or semiology, is the study of signs, symbols, and signification. It is the study of how meaning is created, not what it is. Symbolic (arbitrary) signs: signs where the relation between signifier and signified is purely conventional and culturally specific words.
The circle of fifths produces all major scales with sharps and all major scales with flats. There is also an order of sharps. If there is one sharp it is always F#.