Document cascade_ defaults for custom join conditions

lib/DBIx/Class/Relationship/Base.pm

@@ -383,7 +383,10 @@ be copied too. To turn this behaviour off, pass C<< cascade_copy => 0 >>
 in the C<$attr> hashref.
 
 The behaviour defaults to C<< cascade_copy => 1 >> for C<has_many>
-relationships.
+relationships. If your C<$condition> is a coderef (see L</Custom join conditions>)
+the default changes to C<< cascade_copy => 0 >>, and you need to
+explicitly turn this feature on by passing C<< cascade_copy => 1 >>
+in the C<$attr> hashref.
 
 =item cascade_delete
 
@@ -392,6 +395,11 @@ C<has_one> and C<might_have> relationships. You can disable this
 behaviour on a per-relationship basis by supplying
 C<< cascade_delete => 0 >> in the relationship attributes.
 
+If your C<$condition> is a coderef (see L</Custom join conditions>)
+the default changes to C<< cascade_delete => 0 >>, and you need to
+explicitly turn this feature on by passing C<< cascade_delete => 1 >>
+in the C<$attr> hashref.
+
 The cascaded operations are performed after the requested delete,
 so if your database has a constraint on the relationship, it will
 have deleted/updated the related records or raised an exception
@@ -404,6 +412,11 @@ C<might_have> relationships. You can disable this behaviour on a
 per-relationship basis by supplying C<< cascade_update => 0 >> in
 the relationship attributes.
 
+If your C<$condition> is a coderef (see L</Custom join conditions>)
+the default changes to C<< cascade_update => 0 >>, and you need to
+explicitly turn this feature on by passing C<< cascade_update => 1 >>
+in the C<$attr> hashref.
+
 The C<belongs_to> relationship does not update across relationships
 by default, so if you have a 'proxy' attribute on a belongs_to and want to
 use 'update' on it, you must set C<< cascade_update => 1 >>.