Are really Euler angles?

In several documents, Euler angles are told to be rotations with respect x, y, and z. This is not correct: rotations with respect x,y, and z are the roll, pitch, and yaw angles (RPY). Euler angles are the rotation with respect z, x', and z", where x' is x after first rotation and z" is z after two rotations. Now the question is: the ll functions to convert Euler to Quaternions, is really converting Euler angles, or RPY angles?