I am an achievement junky currently sitting at 686 out of 887 with my codex entries. I have come to the sad truth that the codex system and now even the achievement system they implemented is broken (And I found this post). Many codices can only be obtained from instances that revolve around a certain class. This in itself would not be an issue if they made the codices account/legacy wide so that all characters received it once obtained. Their have also been lore objects I have missed in my own class quests, I would not mind a feature that let me re enter previous story line instances that I have already completed to obtain these (I am not lazy but I already have 8 toons and do not want to roll another for a codex). Certain creatures for the bestiary are not there, for example the 3 on Ilum, I do not think Acidstalker on Taris even exists but if anyone happens to find him let me know. The list goes on. The fact of the matter is they implemented a achievement system that revolves around a codex that is broken. Certain legacy titles are unobtainable and their are going to be some very unhappy people out there because of it.