by ANSI C. Similarly, we assume that the execution character
encoding is a superset of the printable characters of ASCII, though
we don't assume the numeric values of control characters,
-particularly \cw{'\\n'} and \cw{'\\r'}.)
+particularly \cw{'\\n'} and \cw{'\\r'}. Also, the X forwarding code
+assumes that \c{time_t} has the Unix format and semantics, i.e. an
+integer giving the number of seconds since 1970.)
\H{udp-multi-backend} Multiple backends treated equally