Inaccuracy in the description of the positional error in the Chandra catalogue.

In the description of the Chandra catalogue, the column related to the positional error is defined as 

Position error radius at 95% confidence level   //  arcsec   // Position error 95% confidence level circle radius (column also called err_ellipse_r0)

While in the Chandra web page, err_ellipse_r0  is said to be something different

Three of the parameters specifying the geometry of each error ellipse are the semi-major and semi-minor radii (/err_ellipse_r0/, /err_ellipse_r1/), and the position angle θ that the major axis of the ellipse makes with respect to the tangent plane /y/ axis (/err_ellipse_ang/).

What is not actually the same. The difference can be specially relevant when cross matching several set of catalogues/source lists at once.