lauren,
im no expert on greek letters, but i have a chart here, and i know that Phi is a real letter, and all the other letters that could be 'fie' are, in my opinion; xi, pi, chi and psi.
that probably didnt help, but i'll bet someone else knows more than i do
check out the chart of the greek alphabet with the actual greek letters and english names at:
www.msoe.edu/~tritt/greeklr.html
that should be the right address, maybe this will help.
ethan ;o