Because of this feature the keys(), values(), and each() functions
may return the hash elements in different order between different
-runs of Perl even with the same data. One can still revert to the old
-repeatable order by setting the environment variable PERL_HASH_SEED,
-see L<perlrun>. Another option is to add -DUSE_HASH_SEED_EXPLICIT to
-the compilation flags, in which case one has to explicitly set the
-PERL_HASH_SEED environment variable to enable the security feature,
-or -DNO_HASH_SEED to completely disable the feature.
+runs of Perl even with the same data. The additional randomisation
+is enabled if the environment variable PERL_HASH_SEED is set, see
+perlrun for details.
+
+One make the randomisation default by adding -DUSE_HASH_SEED to the
+compilation flags, or completely disable it by adding -DNO_HASH_SEED.
B<Perl has never guaranteed any ordering of the hash keys>, and the
ordering has already changed several times during the lifetime of