In our project the product owner has to fill the backlog with stories, which will be taken by the developers and planned for sprints.
The developers want to be sure they plan only fully specified stories and the product owner wants to be sure he marks each story that is ready as "specified".
Which is the best practice to do this? Should I
a: use the "Resolution" field to include a "specified" value or
b: include a new "status" field into the story definition or
c: should I define a specification board in addition to my board with a workflow like "to do -> in progress -> specified"
d: or is there another best practice for solving this problem?