There is a famous anecdote [0] about Barry Mazur coming up with the worst notation possible at a seminar talk in order to annoy Serge Lang. Mazur defined Ξ to be a complex number and considered the quotient of the conjugate of Ξ and Ξ. (Click link to view 8 lines on top of each other)
[0] https://mathoverflow.net/questions/18593/what-are-the-worst-...