diff --git a/doc/org.texi b/doc/org.texi
index ed53f03f6..4637e6811 100644
--- a/doc/org.texi
+++ b/doc/org.texi
@@ -4569,7 +4569,8 @@ new table.  The @samp{BEGIN} line can specify options:
              @r{Use @kbd{S-@key{left}/@key{right}} keys to shift the time interval.}
 :tstart      @r{A time string specifying when to start considering times}
 :tend        @r{A time string specifying when to stop considering times}
-:step        @r{@code{week} or @code{day}, to split the table into chunks}
+:step        @r{@code{week} or @code{day}, to split the table into chunks.}
+             @r{To use this, @code{:block} or @code{:tstart}, @code{:tend} are needed.}
 :link        @r{Link the item headlines in the table to their origins}
 @end example
 So to get a clock summary of the current level 1 tree, for the current