This week's book giveaway is in the OCAJP forum. We're giving away four copies of Programmer's Guide to Java SE 8 Oracle Certified Associate (OCA) and have Khalid A Mughal & Rolf W Rasmussen on-line! See this thread for details.
Most meta characters loose their meaning inside character classes. Other meta characters change in meaning (^ is start of input outside, negating inside), others are introduced (- is nothing outside, inside it means range unless it's the first character).