I am doing some calculation involving elliptic integrals/functions, and find the notations confusing.

In Wittaker-Watson, the "Jacobi's earlier notation" H(u) is called the Eta-function, so the "H" is not the Latin letter eitch but the Greek capital Eta. Similarly the function Z(u), defined as $\mathrm{Z}(u) = \Theta'(u)/\Theta(u)$, is called the Zeta function, so the "Z" is not the Latin letter zed but the Greek Zeta.

My question is:

(1) What is the notation for E(u) that is related to $\mathrm{Z}(u)$ as E(u) = Z(u) + uE/K? Is it the Latin e, or the Greek capital Epsilon?

(2) The three kinds of elliptic integrals, in Legendre's form, are denoted as $F, E, \Pi$ respectively. I wonder why Latin and Greek notations are mixed. It seems that $\Pi$ have to be Greek, and $F$ have to be Latin. But how about E, it is e or Eta?

I am asking this seemingly trivial question because in common $\LaTeX$ typesetting, capital Latin letters are italic and capital Greek letters are roman (like $Z$ and $\mathrm{Z}$). Thus I want to distinguish them in writing. Whittaker-Watson does not help in this aspect, since all notations are italic in this old book.