diff --git a/SysadminTips.page b/SysadminTips.page
index 5ded8db..d20047b 100644
--- a/SysadminTips.page
+++ b/SysadminTips.page
@@ -1,3 +1,9 @@
+List all software installed from particular component (non-free, contrib)
+
+~~~
+$ dpkg-query -W -f='${Section}\t${Package}\n' | grep ^non-free
+~~~
+
 Manually rotate a file without logrotate, with savelog(8).
 
 ~~~