Are common charges tax deductible for condos

HI everyone, I'm interestedin buying a condo in Manhattan. I'm reading a book about NYC real estate that claims that both real estate taxes AND common charges are fully tax deductible. Is this true? I've been going to some open houses, and a few of them have handed out flyers with sample monthly expense sheets that say that only real estate taxes are tax deductible. (But not common charges.) Why the discrepancy? Was there a recent change in tax law? The book I was reading is from 2004. Any advice/clarification you can give me would be greatly appreciated. Thanks a lot. Khoi