+
+# Fedora Core 5:
+auth include system-auth
+
+# Fedora Core 2:
+#auth required pam_stack.so service=system-auth
+
+# Red Hat 7.3:
+#auth required /lib/security/pam_stack.so service=system-auth
+
+# SuSE 9.0: (along with "configure --with-passwd-helper" and "unix2_chkpwd")
+# auth required pam_unix2.so nullok
+
+# Distant past:
+# auth required /lib/security/pam_pwdb.so shadow nullok