the same procedure used for XMM-LSS and described in @2013MNRAS.429.1652C is applied, i.e. if one detection is in a pointing with a better bad-field flag (column `Xbadfield` in the database), then it is kept in preference to any other. Otherwise if `Xbadfield` is the same, the source closest to the XMM pointing centre (columns `Boffaxis` and `CDoffaxis` in the database) is kept. There is, however, a difference with the XMM-LSS case: `Xbadfield` is not a boolean flag, but can have a range of values:

-   0 : pointing belongs to XXL, has good quality, and is the single or best pointing of a sequence of repeats;

-   1 : pointing does not belong to XXL (archival or deep followup pointing) and has good quality;

-   2 : another XXL pointing in a sequence of repeated pointings (see below) that has good quality;

-   3 : quality is bad (which may occur if the exposure is too shallow, or background is too high, or both).

We note that 94% of the sources have `Xbadfield=0` and only 2% have `Xbadfield=3`.

One should remember that a given pointing might have been re-observed (repeats) if previous observation(s) did not achieve the scheduled exposure. Repeats 