A limited edition is a printing deliberately restricted to a stated number of copies, often numbered and signed, and usually better made than the ordinary trade edition, with finer paper, binding or illustrations.
How to spot it
Look for a limitation statement, typically at the front or back: "This edition is limited to 500 copies, of which this is number 132", often with the author's or artist's signature. Check that the number is filled in by hand and that the copy matches the description, for example the special binding or slipcase. Some publishers issued signed limited editions alongside the trade first.
What it does to value
A limited edition's value depends on the book, the size of the edition and whether it is signed. Small signed limited editions of important books can be worth more than the trade first edition. Large limited editions of everyday titles may be worth little more than the trade edition. Missing slipcases or certificates lower value.
Read limited and special editions for how to read limitation statements, and see special editions for modern box and bookshop editions.