print-gensym

print-gensym is a variable defined in `C source code'.
Its value is

nil

Documentation:
Non-nil means print uninterned symbols so they will read as uninterned.
I.e., the value of (make-symbol "foobar") prints as #:foobar.
When the uninterned symbol appears within a recursive data structure,
and the symbol appears more than once, in addition use the #N# and #N=
constructs as needed, so that multiple references to the same symbol are
shared once again when the text is read back.