+=item Variable "%s" may be unavailable
+
+(W) An inner (nested) I<anonymous> subroutine is inside a I<named>
+subroutine, and outside that is another subroutine; and the anonymous
+(innermost) subroutine is referencing a lexical variable defined in
+the outermost subroutine. For example:
+
+ sub outermost { my $a; sub middle { sub { $a } } }
+
+If the anonymous subroutine is called or referenced (directly or
+indirectly) from the outermost subroutine, it will share the variable
+as you would expect. But if the anonymous subroutine is called or
+referenced when the outermost subroutine is not active, it will see
+the value of the shared variable as it was before and during the
+*first* call to the outermost subroutine, which is probably not what
+you want.
+
+In these circumstances, it is usually best to make the middle
+subroutine anonymous, using the C<sub {}> syntax. Perl has specific
+support for shared variables in nested anonymous subroutines; a named
+subroutine in between interferes with this feature.
+
+=item Variable "%s" will not stay shared
+
+(W) An inner (nested) I<named> subroutine is referencing a lexical
+variable defined in an outer subroutine.
+
+When the inner subroutine is called, it will probably see the value of
+the outer subroutine's variable as it was before and during the
+*first* call to the outer subroutine; in this case, after the first
+call to the outer subroutine is complete, the inner and outer
+subroutines will no longer share a common value for the variable. In
+other words, the variable will no longer be shared.
+
+Furthermore, if the outer subroutine is anonymous and references a
+lexical variable outside itself, then the outer and inner subroutines
+will I<never> share the given variable.
+
+This problem can usually be solved by making the inner subroutine
+anonymous, using the C<sub {}> syntax. When inner anonymous subs that
+reference variables in outer subroutines are called or referenced,
+they are automatically rebound to the current values of such
+variables.
+
+=item Variable syntax