You mean you have to use clear plastic bags for your rubbish, Azizi? That could look a bit yukky... Plus of course there's the matter of privacy.

I suppose it would reduce the risk of chucking out the stuff you hadn't meant to chuck out.

Bin liners aren't quite the same thing, though they might be. I mean there are special plastic bags to use to put in your rubbish bin in the kitchen, so you can lift it out and put it out to be collected. But we tend to use the same all-purpose bags that you can buy in rolls of 10, 50 or whatever. (Which generally are black. If they aren't they still tend to be referred to that way - "We need some more green black plastic bags". Rather like "black taxi-cabs" which these days can come in all colours of the rainbow.)