X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/481eeb93961ef9998901c522b498253d75124fb4..a1caa6da6f72e8c5b8b24678e32c4953a26a2b48:/doc/doc-docbook/spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index d030a8411..d71d3696f 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -2886,6 +2886,11 @@ available to admin users.
 
 The word &"set"& at the start of a line, followed by a single space,
 is recognised specially as defining a value for a variable.
+.new
+.cindex "tainted data" "expansion testing"
+If the sequence &",t"& is inserted before the space,
+the value is marked as tainted.
+.wen
 The syntax is otherwise the same as the ACL modifier &"set ="&.
 
 .cmdopt -bem <&'filename'&>