Another way is to assign to a substr() that's off the end of the string.
-=item Modification of non-creatable array value attempted, subscript %d
+=item Modification of non-creatable array value attempted, %s
(F) You tried to make an array value spring into existence, and the
subscript was probably negative, even counting from end of the array
backwards.
-=item Modification of non-creatable hash value attempted, subscript "%s"
+=item Modification of non-creatable hash value attempted, %s
(P) You tried to make a hash value spring into existence, and it
couldn't be created for some peculiar reason.
(F) Only a bare module name is allowed as the first argument to a "use".
-=item Module name required with -M option
+=item Module name required with -%c option
-(F) The C<-M> option says that Perl should load some module, but you
-omitted the name of the module. Consult L<perlrun> for full details
-about C<-M>.
+(F) The C<-M> or C<-m> options say that Perl should load some module, but
+you omitted the name of the module. Consult L<perlrun> for full details
+about C<-M> and C<-m>.
=item msg%s not implemented
(F) More than 100 levels of inheritance were used. Probably indicates
an unintended loop in your inheritance hierarchy.
-=item Recursive inheritance detected while looking for method '%s' in package '%s'
+=item Recursive inheritance detected while looking for method %s
(F) More than 100 levels of inheritance were encountered while invoking
a method. Probably indicates an unintended loop in your inheritance
"abc" provided that it is followed by three repetitions of "xyz" is
C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
-=item Stub found while resolving method `%s' overloading `%s' in package `%s'
+=item Stub found while resolving method `%s' overloading %s
(P) Overloading resolution over @ISA tree may be broken by importation
stubs. Stubs should never be implicitly created, but explicit calls to
defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
To suppress this warning assign a defined value to your variables.
+To help you figure out what was undefined, perl tells you what operation
+you used the undefined value in. Note, however, that perl optimizes your
+program and the operation displayed in the warning may not necessarily
+appear literally in your program. For example, C<"that $foo"> is
+usually optimized into C<"that " . $foo>, and the warning will refer to
+the C<concatenation (.)> operator, even though there is no C<.> in your
+program.
+
=item Value of %s can be "0"; test with defined()
(W misc) In a conditional expression, you used <HANDLE>, <*> (glob),