diff --git a/Quality-Assurance-(QA).md b/Quality-Assurance-(QA).md
index eb89fad..c4c0017 100644
--- a/Quality-Assurance-(QA).md
+++ b/Quality-Assurance-(QA).md
@@ -62,6 +62,26 @@
 5. on your real desktop (not inside the Xephyr window) ```cd client/X11``` and try if you can open 10 concurrent xfreerdp sessions to the shadow server: ```for i in `seq 1 10`; do ./xfreerdp /v:realipaddress /cert-ignore & done``` (don't use localhost or 127.0.0.1)
 6. test connecting to the shadow server using Microsoft's Android, Mac OSX, iOS, Windows CE/RT/XP/Vista/7/8 clients
 
+***
+
+# Clients
+
+## X11: xfreerdp
+
+### Smart-Sizing
+- Microsoft's description of that feature: http://blogs.msdn.com/b/rds/archive/2008/08/07/smart-sizing-the-ts-client.aspx
+- Support in FreeRDP was added with this PR: https://github.com/FreeRDP/FreeRDP/pull/2240
+
+**Basic usage:**
+- make window resizable, scaling contents: xfreerdp /v:servername /smart-sizing 
+- create a 1024x768 session but display the session down-scaled in a 640x480 window: xfreerdp /v:servername /size:1024x768 /smart-sizing:640x480
+- create a 640x480 session but display the session up-scaled in a 1024x768 window: xfreerdp /v:servername /size:640x480 /smart-sizing:1024x768
+
+**Fullscreen-toggling**
+- If the session was started with /smart-sizing and you enter fullscreen mode via Ctrl+Alt+Enter the session is expected to get scaled to the fullscreen dimensions.
+- If you leave fullscreen mode again the window should resize to the dimension it had before switching to fullscreen.
+
+***
 
 # Virtual Channels
 
@@ -130,4 +150,4 @@
 
 ## Remote Assistance Protocol
 - Channel name: Multiple: "RC_CTL", "70", "71", ".", "1000.", "RA_FX" 
-- Specification: [MS-RA](https://msdn.microsoft.com/en-us/library/cc240013.aspx)
+- Specification: [MS-RA](https://msdn.microsoft.com/en-us/library/cc240013.aspx)
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