From the back cover:
THE DUNGEON ALPHABET
Expanded Third Printing
An A-to-Z reference for classic dungeon design.
Designing dungeons is as easy as A, B, C!
The Dungeon Alphabet compiles inspirational tables of classic dungeon design elements to assist the Game Master in creating subterranean challenges. This third printing adds eight new topics to the existing twenty-six for thirty-four tables of inspirational materials.
A is for Altar, B is for Books, and C is for Caves: The Dungeon Alphabet has advice, hints, and randomized tables that bring new life to your adventures.
The entries are accompanied by outstanding art from classic fantasy illustrators and are compatible with all fantasy role playing games.
this is the expanded edition of The Dungeon Alphabet