- Also mention ?= in the general section on boot parameters

- The url expansion magic only works in auto mode, so don't mention it in the general boot parameter section

1 files changed, 10 insertions, 4 deletions

diff --git a/en/appendix/preseed.xml b/en/appendix/preseed.xml
index 8d133ec75..bc8515ac2 100644
--- a/en/appendix/preseed.xml
+++ b/en/appendix/preseed.xml
@@ -330,12 +330,18 @@ during the configuration of the relevant package.
 
 </para><para>
 
+Normally, preseeding a question in this way will mean that the question will
+not be asked. To set a specific default value for a question, but still have
+the question asked, use <quote>?=</quote> instead of <quote>=</quote> as
+operator. See also <xref linkend="preseed-seenflag"/>.
+
+</para><para>
+
 Note that some variables that are frequently set at the boot prompt
 have a shorter alias. If an alias is available, it is used in the
-examples in this appendix instead of the full variable.  In
-particular, the <literal>preseed/url</literal> variable has been
-aliased as <literal>url</literal> and has some extra magic to allow
-shortened urls to be used. Another example is the <literal>tasks</literal>
+examples in this appendix instead of the full variable. The
+<literal>preseed/url</literal> variable for example has been aliased as
+<literal>url</literal>. Another example is the <literal>tasks</literal>
 alias, which translates to <literal>tasksel:tasksel/first</literal>.
 
 </para><para>