diff --git a/extension/Documentation/Manual.rst b/extension/Documentation/Manual.rst
index e81afa316955aefeaa56006e6b7f519f0212db07..b56ce14be7fa1d8addb7193ea9addcdf91b9bd6d 100644
--- a/extension/Documentation/Manual.rst
+++ b/extension/Documentation/Manual.rst
@@ -5151,6 +5151,21 @@ Column: _link
 Render mode
 ^^^^^^^^^^^
 
+The following table might be hard to read - but it's really useful to understand. It solves a lot of different situations.
+If there are no special condition (like missing value, or suppressed links), render mode 0 is sufficient.
+But if the URL text is missing, or the URL is missing, OR the link should be rendered in sql row 1-10, but not 5, than
+render mode might dynamically control the rendered link.
+
+* Horizontal:
+
+  * If 'url & text' is given, column 2 shows the result.
+  * If only 'url' is given, column 3 shows the result.
+  * If only 'text' is given, column 4 shows the result.
+
+* Vertical:
+
+  * Column 0 is the render mode and controls how the link is rendered.
+
 +-----------+--------------------+-------------------+----------+-----------------------------------------------------------------------+
 |Mode       |Both: url & text    |Only: url          |Only: text|Description                                                            |
 +===========+====================+===================+==========+=======================================================================+
@@ -5171,6 +5186,10 @@ Render mode
 |7          | pure url           |pure url           |          |no link, pure url                                                      |
 +-----------+--------------------+-------------------+----------+-----------------------------------------------------------------------+
 
+::
+
+    10.sql = SELECT CONCAT('u:', p.homepage, IF(p.showHomepage='yes','|r:0', '|r:5') ) AS _link FROM Person AS p
+
 
 Link Examples
 ^^^^^^^^^^^^^