My brother in California recently had a problem with an "Evil penny" cache. He glued a penny to to the lid of a small tube and placed it into the ground so that a person walking by would only see the penny. Now in my opinion a penny that is glued to the lid is now an extension of the container, so part of the container is even with the surface of the ground. By definition* this cache is not "buried." Reviewer refused to publish cache citing "buried."
*Since it is easiest to just google the definition of "buried," this is the definition I go by.