Originally Posted by .:Lord Revan:.
How i think is, Dark Lord: Leader of the sith
Sith Lord: Sith Master
Darth: is given to someone when they reach Sith Lord.
Hope this helps
Except that *Darth* is given to those who are [keywords]acknowledged[/keywords] as being *Sith* by their *Masters*, otherwise everything else is true, except for Dark Jedi who are like --- tweeners or something