> That is doubly not true: > 1. The use of bare 'na' etc. has been deprecated since 5.005-ish. > 2. There is a work round by setting POLLUTE - so compatibility _is_ built in. I've worked around this in the past by doing the following: #ifndef PL_na #define PL_na na #endif #ifndef PL_sv_undef #define PL_sv_undef sv_undef #endif To provide backwards compatibility with old perls. This works fine in 5.005_03, but breaks in 5.6.0. What is the correct incantation that preserves backwards compatibility? Alan Burlison