Some sort of curtain fastening arrangement seems to be the best explanation. I think I'll call that a win.

*Contentious statement alert* Most unidentified objects in abandoned drawers and neglected biscuit tins of 'things' are to do with hanging curtains. Curtains are the most complicated of household artefacts and no two systems are interchangeable or compatible.

[pen] Ha! You've obviously never had to deal with shelving units...

[Pabbers] Ha! I have a husband to deal with that sort of thing.

[pen] Now that's a bloody good idea! Why didn't I think of that?