Document BLOCKED property

doc/ChangeLog

@@ -1,3 +1,7 @@
+2010-03-15  Carsten Dominik  <carsten.dominik@gmail.com>
+
+	* org.texi (Special properties): Document the BLOCKED property.
+
 2010-03-14  Carsten Dominik  <carsten.dominik@gmail.com>
 
 	* org.texi (The spreadsheet): Mention the formula editor.

doc/org.texi

@@ -4463,6 +4463,7 @@ used as keys in the properties drawer:
 @cindex property, special, TIMESTAMP
 @cindex property, special, TIMESTAMP_IA
 @cindex property, special, CLOCKSUM
+@cindex property, special, BLOCKED
 @c guessing that ITEM is needed in this area; also, should this list be sorted?
 @cindex property, special, ITEM
 @example
@@ -4478,6 +4479,7 @@ TIMESTAMP    @r{The first keyword-less timestamp in the entry.}
 TIMESTAMP_IA @r{The first inactive timestamp in the entry.}
 CLOCKSUM     @r{The sum of CLOCK intervals in the subtree.  @code{org-clock-sum}}
              @r{must be run first to compute the values.}
+BLOCKED      @r{Set if task is currently blocked by children or siblings}
 ITEM         @r{The content of the entry.}
 @end example