There is an important difference between deleting an attribute and deleting an attribute application.
Deleting an attribute application disassociates the attribute with the chosen body/face/edge. The attribute itself is not deleted and can later be applied to other bodies/faces/edges. Deleting an attribute, however, deletes all associated applications and the attribute.
To delete an attribute application from a body/face/edge, pick it and press the Space bar. Next select the desired application in the list box on the left side of the dialog box and click . Alternatively, pick the body/face/edge that you want to modify and then on the Structure ribbon in the Attributes group, click and choose the desired attribute application to remove (by name).
To delete all applications of a given attribute, right-click the node for the attribute in the Browser and selection Remove All Applications from the context menu. The attribute will move to the Unused folder for the attribute type.
To delete an attribute, either right-click it and choose Delete.from the context menu or select the attribute node and press