Mathematical formulas and other expressions involving special symbols, character positions, and relationships may present difficulties in clarity in print and online publications. Careful markup (clarifying the symbols used and superior and inferior characters), avoidance of ambiguity through proper use of parentheses and brackets, and adherence to typographic conventions and capitalization rules in equations require special note (see also 8.5, Punctuation, Parentheses and Brackets, and 22.0, Typography).