Incomplete documentation of field Dashboard widget field "name"

The optional field "name" has just description "Widget field name" as if it would be just insignificant field, field UI label.
But at least for field type 6 (graph) the name has to have contents "graphid" otherwise no graph is displayed in the dashboard (when defining dashboard through API) and it is not easy to discover.

Maybe other types need some special value in "name" field, too, I did not try them out.