diff -r 430dd9517382 -r aeb2f717165d src/source/install.rst
--- a/src/source/install.rst	Sat Jan 27 01:26:33 2018 +0100
+++ b/src/source/install.rst	Sat Jan 27 01:27:02 2018 +0100
@@ -146,6 +146,9 @@
   variables (see below).
 
 
+Boolean values accept "true", "yes", "on" or "1" (in any case) as *true* values, and anything else as *false*; setting
+any option to empty string will keep the default proposed value.
+
 You can then check, and eventually update, the proposed Buildout configuration file *buildout.cfg*, to add or remove
 packages or update settings to your needs. Then finalize Bootstrap initialization: