What's this symbol called?

[Dawoodusmani]

What is this symbol :- called and where do you use it? Is this an English punctuation mark?

[Dozy]

According to http://books.google.co.uk/books?id=CSUtOYO9AmAC&pg=PA87 it is (or was) known to printers as a "full set". I imagine few people know that name; I'd certainly never heard it. I guess most people would just call it "colon-dash" or "colon and dash".

In English, it is used like a colon (to introduce lists of items, for example). To me, it has a rather old-fashioned or specialised feel -- something you might expect to see in an old legal document, say. The book referenced above also calls it an "old style". In modern English it has been mostly superseded by the plain colon.