diff -up man-pages-3.40/man5/nsswitch.conf.5.orig man-pages-3.40/man5/nsswitch.conf.5
--- man-pages-3.40/man5/nsswitch.conf.5.orig	2012-04-27 00:58:39.000000000 +0200
+++ man-pages-3.40/man5/nsswitch.conf.5	2012-04-27 14:25:22.453203872 +0200
@@ -46,6 +46,11 @@ The following databases are understood b
 Mail aliases, used by
 .BR getaliasent (3)
 and related functions.
+It provides a system-wide mechanism to redirect mail for local
+recipients. Used by mail transfer agents such as Postfix or
+.BR sendmail (8).
+Note: On Linux, not like on other Unices, Sendmail uses its own aliases
+resolution system independent on `/etc/nsswitch.conf'.
 .TP
 .B ethers
 Ethernet numbers.