This article is from the Esperanto FAQ, by Mike Urban firstname.lastname@example.org and Yves Bellefeuille email@example.com with numerous contributions by others.
Esperanto has six letters with accents: c, g, h, j, and s can have a
circumflex accent (^), and u can have a breve accent (similar to the
lower half of a small circle).
All modern operating systems, word processing programs, etc., can handle
these characters. Usually all that is required is to type some
combination of keys to represent them. However, "dumb" terminals
generally cannot overstrike accents with arbitrary characters, and so
cannot display Esperanto's accented characters, or any other language