Is it "policy(ies)" or policy(s)" for an optional, parenthetical plural suffix?

Question

When writing a noun that shows a parenthetical plural suffix option, which is acceptable, "policy(ies)" or policy(s)"?

Answer 1

Since the difference between the words is not a simple addition of characters, using parenthesis to show the optional form is not clear.

Instead, it would be clearer to write:

policy (or policies).