* doc/org.texi (Property syntax): Recall the user to refresh the org
buffer when properties are set on a per-file basis.
TINYCHANGE
#+PROPERTY: NDisks_ALL 1 2 3 4
@end example
+Contrary to properties set from a special drawer, you have to refresh the
+buffer with @kbd{C-c C-c} to activate this changes.
+
If you want to add to the value of an existing property, append a @code{+} to
the property name. The following results in the property @code{var} having
the value ``foo=1 bar=2''.