How do I add my own new traits?

[Cía]

I have thought about this question for a while now and I am asking you people for help.
What I want is to add 3-4 new traits to the game but I don't know how to do it.
Could someone please tell me which XML files I have to look?

 

[Popcornlord]

XML\Civilizations\CIV4TraitInfos for defining the traits, XML\Civilizations\CIV4LeaderHeadInfos for adding them. Have fun modding.