+You can also return to an upper level and know which context was in use then.
+
+=head1 WORDS
+
+These control words are to be used to indicate the target scope.
+
+=head2 C<TOP>
+
+Returns the level that currently represents the highest scope.
+
+=head2 C<HERE>
+
+The current level.
+
+=head2 C<UP $from>
+
+The level of the scope just above C<$from>.
+
+=head2 C<SUB $from>
+
+The level of the closest subroutine context above C<$from>.
+
+=head2 C<EVAL $from>
+
+The level of the closest eval context above C<$from>.
+
+If C<$from> is omitted in any of those functions, the current level is used as the reference level.
+
+=head2 C<CALLER $stack>
+
+The level of the C<$stack>-th upper subroutine/eval/format context.
+It kind of corresponds to the context represented by C<caller $stack>, but while e.g. C<caller 0> refers to the caller context, C<CALLER 0> will refer to the top scope in the current context.