The invention describes a lid for a container comprising an edge region (2) for sealing and permanent connection to a container body comprising a body portion and a bottom, and a substantially flat central region as a panel or lid surface (3), on which at least one projecting pin-like or post-like guide element (7′, 7″, 8) is formed extending from the panel (3) towards one side or the other substantially parallel to an axis (9) perpendicular to the lid surface. The posts can guide additional elements which are intended to form a functional unit with the lid.