Game Mechanics: /target requires line of sight?

[Orruar]

For players, not corpses, /target requires line of sight. I saw a few random comments and threads about this topic elsewhere on these forums, but no definitive proof one way or the other. Does anyone have a link to a page with all previous patch notes that I could search through? I'm pretty sure that as far back as when I started raiding in Luclin, you could target players not in line of sight using /target.