Okay I don't get what it means by Defensive targeting and grouping is restricted on team servers. Is it just about about the obvious no teaming with members of the opposing side or what? If somebody could clear that up for me I'd really appreciate it :).

Yes that is exactly what it means. No teaming with. No guild/grouping with. No heal/Buffing the OTHER team.

WC

Thanks, that has been driving me crazy.

If you haven't played the game yet, you can have an offensive and defensive target at the same time. This makes it much easier for most classes to use their skills effectively, such as a healer being able to target a mob but heal a teammate without losing their offensive target, or a tank to rescue a healer that's getting clobbered. On the PVP team server the other team always shows up as an offensive target, which means you can only attack them and can't use skills like heals/buffs/rescues. This also means that using TAB to target will cause people of the other team to be targetted (since TAB sets the offensive target) but not members of your own team. Instead Shift+TAB (I think that's the default) will work to set your defensive target to a teammate.