allows to have at least 65536 characters (what is called the BMP, or basic
multilingual plane) and possible $2^{32}$ of them instead of the usual 256 and
is sufficient to encode all of the world languages at once. More details about
-Unicode may be found at {\tt www.unicode.org}.
+Unicode may be found at \urlref{http://www.unicode.org}{http://www.unicode.org}.
% TODO expand on it, say that Unicode extends ASCII, mention ISO8859, ...