Well, even a contrived example will be fine, so let's use...
partial class workitem
private int id;
private string title;
private string description;
private int project_id;
private int assignee_id;
private int estimated_remaining_hours;
private DateTime estimated_eta;
private int status_id;
.. and please implement that 'estimated_remaining_hours' and 'estimated_eta fields' are only valid for certain values of status_id (this maps to statuses such as 'open issue', 'workitem completed' etc).
Greying out would be OK, but even better UI would be to hide irrelevant fields based on some of the parameters. Also it needs to be dynamic, since the user can change the workitem status as they edit the workitem.