MathJax Equation Tags

 Equations can get reference numbers using the \tag{} macro, e.g: $E=mc^2\tag{1}$ produces $E=mc^2\tag{1}$ Note that the contents of \tag{} are in text mode, so if you want to include math symbols, use \tag{$...$}. E.g., $E=mc^2\tag{\bullet}$ produces $E=mc^2\tag{\bullet}$