@item @file{all} target is default
@item @file{stdout} is always captured, but no target is created if it
was empty
-@item empty targets are considered always out of date
+@item non-existent targets are considered always out of date
@item @file{.do}'s @file{$3} is relative path to the file in target directory
@item @file{.do} search goes up to @file{/} by default, but can be
limited with either @env{$REDO_TOP_DIR} environment variable, or by