cntrl includes several more characters than are currently documented, namely also ASCII DEL (127) and non-ASCII 128-159.
Missing closing bracket for the examples given for digit/1 and xdigit/1.
Also note that those
x for which
char_type(x,graph) succeeds form a strict subset of the answers of
char_type(VAR, graph) (the generative case does not go beyond character code 255).