Thanks Rob, I've searched perl5.30 source, there still has some parts to test pPOK flag. I guess maybe pXOK flag indicate this SV is used for perl internal. (can't see and use from outside) but since 5.18 onward, pXOK maybe desprecated, and replaced by XOK.

In reply to Re^2: what does private/public data mean in Devel::Peek by Anonymous Monk
in thread what does private/public data mean in Devel::Peek by xiaoyafeng

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