+A string beginning with C<'@'> or C<'%'>, for which the call is equivalent to respectiveley C<local $a[$key]; delete $a[$key]> and C<local $h{$key}; delete $h{$key}>.
+
+=item *
+
+A string beginning with C<'&'>, which more or less does C<undef &func> in the upper scope.
+It's actually more powerful, as C<&func> won't even C<exists> anymore.
+C<$key> is ignored.
+
+=back
+
+=head2 C<unwind @values, $context>
+
+Returns C<@values> I<from> the context pointed by C<$context>, i.e. from the subroutine, eval or format just above C<$context>, and immediately restart the program flow at this point - thus effectively returning to (or from, depending on how you see it) an upper context.
+
+The upper context isn't coerced onto C<@values>, which is hence always evaluated in list context.
+This means that
+
+ my $num = sub {
+ my @a = ('a' .. 'z');
+ unwind @a => HERE;
+ }->();
+
+will set C<$num> to C<'z'>.
+You can use L</want_at> to handle these cases.
+
+=head2 C<want_at $context>
+
+Like C<wantarray>, but for the subroutine/eval/format just above C<$context>.
+
+The previous example can then be "corrected" :
+
+ my $num = sub {
+ my @a = ('a' .. 'z');
+ unwind +(want_at(HERE) ? @a : scalar @a) => HERE;
+ }->();
+
+will righteously set C<$num> to C<26>.
+
+=head1 WORDS
+
+=head2 Constants
+
+=head3 C<TOP>
+
+Returns the context that currently represents the highest scope.
+
+=head3 C<HERE>
+
+The context of the current scope.
+
+=head2 Getting a context from a context
+
+For any of those functions, C<$from> is expected to be a context.
+When omitted, it defaults to the the current context.
+
+=head3 C<UP $from>
+
+The context of the scope just above C<$from>.
+
+=head3 C<SUB $from>
+
+The context of the closest subroutine above C<$from>.
+
+=head3 C<EVAL $from>
+
+The context of the closest eval above C<$from>.
+
+=head2 Getting a context from a level
+
+Here, C<$level> should denote a number of scopes above the current one.
+When omitted, it defaults to C<0> and those functions return the same context as L</HERE>.
+
+=head3 C<SCOPE $level>
+
+The C<$level>-th upper context, regardless of its type.
+
+=head3 C<CALLER $level>
+
+The context of the C<$level>-th upper subroutine/eval/format.
+It kind of corresponds to the context represented by C<caller $level>, 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.