$ perl -le'print for %Internals::'
SvREFCNT
*Internals::SvREFCNT
hv_clear_placeholders
*Internals::hv_clear_placeholders
hash_seed
*Internals::hash_seed
SvREADONLY
*Internals::SvREADONLY
HvREHASH
*Internals::HvREHASH
rehash_seed
*Internals::rehash_seed