  We define a variable-length code having the property that no (non-empty)
prefix of each its codeword is a suffix of any other one, and vice versa. This
kind of code can be seen as an extension of two well-known codes in literature,
called respectively fix-free code and non-overlapping code. In this paper, some
constructive algorithms for such codes are presented as well as numerical
results about their cardinality.
