You are spot on!
I did 
printf "version is v%vd\n", $^V;  # Perl's version

[download]
and got v5.8.9. Then I checked the perldoc ref for 5.8.9 and VSTRING is not present.

In reply to Re^2: Question about Perl refs and basic types by cheekuperl
in thread Question about Perl refs and basic types by cheekuperl

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