Maybe it's trying to encourage you to specify the return value explicitly, as in 

return undef;

[download]
or 
return ();

[download]

Update: Here's a table of the differences:

return undef; return (); return;
scalar $sv = foo(); undef undef undef
boolean if (foo()) { } false false false
string '' . foo() '' with warning '' with warning '' with warning
number 0 + foo() 0 with warning 0 with warning 0 with warning
list my @a = foo(); ( undef ) ( ) ( )
boolean list assignment if (my @a = foo())
if (my ($sv) = foo())
if (() = foo()) 		true false false
scalar list assignment my $sv = () = foo() 1 0 0

Note: How list assignments are treated in scalar context is what allows
while (my ($key) = each(%hash))
to work even if there's a key named 0.

In reply to Re^2: Module Announcement: Perl-Critic-1.01 by ikegami
in thread Module Announcement: Perl-Critic-1.01 by jthalhammer

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