The fastening hold clinggo spot is integrated into tunnel lining segments shortly prior to casting. The formwork plugs are made of tempered steel and are virtually wear-free. First they are screwed into the tunnel lining segments. Then the clinggo spot is manually attached to the formwork elements and the concrete is poured. Due to the signal colour of the membrane remaining visible, the fastening holds are readily discernible, even in the artificial light of the construction site.