Contraindication of using a bar type direct retainer is:
Gingivally approaching clasps (e.g. bar clasp) is contraindicated in severe soft tissue (gingival) undercut.
In such cases, occlusally approaching clasp configurations are more suitable.
Used on a distobuccal on terminal abutments
When aesthetics demand less display of metal
When a push type of retention is needed
When a large tissue undercut is present