Add a usage note about the "l" modifier.

diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod
index d509eee..e864147 100644 (file)
--- a/pod/perlfunc.pod
+++ b/pod/perlfunc.pod
@@ -8223,6 +8223,11 @@ as supported by the compiler used to build Perl:
    z           interpret integer as C types "size_t" or
                "ssize_t" on Perl 5.14 or later
 
+Note that, in general, using the C<l> modifier (for example, when writing
+C<"%ld"> or C<"%lu"> instead of C<"%d"> and C<"%u">) is unnecessary
+when used from Perl code.  Moreover, it may be harmful, for example on
+Windows 64-bit where a long is 32-bits.
+
 As of 5.14, none of these raises an exception if they are not supported on
 your platform.  However, if warnings are enabled, a warning of the
 L<C<printf>|warnings> warning class is issued on an unsupported