T-bars

T-bars are small, elongated pins through which either a cord or a ribbon can be looped. This bar with the loop can be attached to a fabric and can be used much like a button.

You can thread it through a buttonhole and also simply unthread it. Or, which is the special advantage, lead it through a fixed ring made of plastic or metal and thus creating a flexible connection that can be easily released again. This connection is often used in tents where the inner tent is hooked into the outer tent.