User blog comment:Dark Swarmlord/Subject Psi/@comment-3966801-20111015124344/@comment-1330314-20111015212849

When you create or edit an article, click on the small "more" button next to the toolbar, and it should open a window with a selection of special characters. The letters phi and psi should be in the Greek section. Alternatively, if you want to insert them in a blog post, do a Google search on it and copy-paste the character you want.