Caution... This is new information provided by a very new book. Caution...
Star Wars: Knights of the Old Republic Campaign Guide
Darth Traya, Lord of Betrayal
...Intrigued, Kreia scours the texts through the Force, suspecting their authors were in fact pureblooded descendants of the Sith people.
We have a conflict with the meaning of true Sith. Revan is looking for the true Sith menace. Kreia studied from books in which she believed were written by the pureblooded descendants of the Sith people. Could this be the original Korriban descendants?
I think we are all correct in some weird way. We need more input. More data please.
Calling Lucas now.