Consider this example from the Rogue class traits:
Trained Skills: Stealth and Thievery. From the class skills list below, choose four more trained skills at 1st level.
Class Skills: Acrobatics (Dex), Athletics (Str), Bluff (Cha), Dungeoneering (Wis), Insight (Wis), Intimidate (Cha), Perception (Wis), Stealth (Dex), Streetwise (Cha), Thievery (Dex)
The Rogue is trained in Stealth and Thievery. However, they're also included in the Class Skills section, and it invites you to: 'choose four more trained skills' from that list. This seems to be similar for all the classes.
So can you train Stealth and Thievery as a choice as well have it initially trained or the equivalent for other classes?