A microblog post by @kareem_carr saying "as soon as i saw they were using asterisks for multiplication symbols, i knew we were in trouble", with an image from the "Office of the United States Trade Representative (Executive Office of the President)" showing the mathematical formula
$\Delta \tau_i = \frac{x_i - m_i}{\varepsilon * \varphi * m_i}$. The formula show asterisks (*) instead of multiplication signs (×).
Just guessing but real mathematicians would know how to properly build the formula. I guess in higher maths we use the 'x' rather than '*'.
Not a big deal but may show that the people doing it have no idea what they are doing.
Typically you'd use either nothing (just put the symbols next to each other) or in cases where that would be unclear, you'd use the centered dot ⋅