[Chicken-hackers] Invalid forwarded object howto?

[Jörg F . Wittenberger]

Please could somebody enlighten me, what those forwarded
objects are?  A short note on purpose and encoding should
be enough.

The real question would be: how can it happen, that I
can create an invalid forwarded object - or for that matter -
how would I avoid it?

A different though related question:  I found that when
"member" tests against a list, which turns out to be
an invalid forwarded object when printed, it may
segfault.

Thanks for any hint!

/Jerry
......