If the object approval feature is enabled for your repository then only objects that have been explictly approved will appear in your repository's catalog, be returned from your repository's search pages, or be available for interoperation. If the object approval feature is not enabled for your repository then changing an object's status has no effect. See help on Manage Catalog / Object Approval for more information on this feature.
To approve or unapprove objects in your reposiory, click the "Manage Objects" tab and then select objects' class. Next select (left-click) the object(s) whose status you wish to change. CTRL+left-click toggles the selection on individual objects and SHIFT+left-click allows you to select a range of objects. Right-click your selection and a popup menu will appear. Choose "Set status" and select "Approved" or "Not Approved".