*Foo{SCALAR} = SCALAR(0x511f4)  # original entry in glob
$x = SCALAR(0x511f4)            # ref to original scalar (same)
$Foo = 5                        # original value
Enter scope
*Foo{SCALAR} = SCALAR(0x47650)  # new SCALAR entry in glob
$y = SCALAR(0x47650)            # ref to it
$Foo = 42                       # value of localized var
$$x = 5                         # value of original
$$y = 42                        # value via ref to localized var
$Foo = 42                       # after editing original, local unchanged
Exit scope
*Foo{SCALAR} = SCALAR(0x511f4)  # original entry back in glob
$Foo = 6                        # change we made via $$x now visible
$y = SCALAR(0x47650)            # the localized var still around via ref
$$y = 42                        # still contains value