Other Uses
In chemistry, the minus sign (rather than an en dash) is used for a single covalent bond between two atoms, in skeletal formula.
Subscripted plus and minus signs are used as diacritics in the International Phonetic Alphabet to indicate advanced or retracted articulations of speech sounds.
The minus sign is also used as tone letter in the orthographies of Dan, Krumen, Karaboro, Mwan, Wan, Yaouré, Wè, Nyabwa and Godié. The Unicode character used for the tone letter (U+02D7) is different from the mathematical minus sign.
Read more about this topic: Plus And Minus Signs