Which edition/printing do I have?

If it has a blue "Updated..." stripe across the top of the front cover, it's the updated edition; if not, it's the first, UML1.1, edition. To tell which printing you have look inside to the left of the Contents page. You'll see a strip of numbers e.g.

10 9 8 7 6 5 4 3 2

The right-hand number tells you which printing you have, e.g. the example above is the second printing (of some edition).

If you have a translation or the Low Priced Edition (for the Indian subcontinent) you probably have the First Edition text, in some language.