A    The X-ray source matches well with one 24um source. Both the X-ray to 
A     optical and 24um to optical matches indicate that the first optical source
A     is most likely to be the true counterpart.
B    The 24um matches are low probability, but are included here as one of the
B     possible counterparts is a supercluster galaxy.
C    The two optical and two 24um detections are both components of a local 
C     merging system.
D    The 24um catalogue includes multiple detections of the same object. 
D     The combined flux is given.
E    The X-ray-optical match has low probability, but it becomes more likely 
E     once the 24um data are added.
F    The 24um data reduce two optical possibilities to one. The 24um-X-ray 
F     match is excellent (0.99) but the match with the optical source is lower
F     significance as the source is very faint.
G    24um data reduce two equally likely X-ray  optical matches to one secure 
G     match. The rejected match is a very bright star, which is actually 2 away.
H    The 24um source is well matched to the optical counterpart, and is likely
H     to be the source of the X-rays.
I    The X-ray-optical match gives a number of possible counterparts. All are 
I     rejected, as the 24um source is an excellent match with the X-ray (0.98)
I     and is not associated with any of these sources. The most likely match 
I     is a very faint source, which is listed.
QSO  The optical source is a QSO, and therefore has a higher likelihood of 
QSO   being the true counterpart than indicated by the probabilities.
Star The optical source is a star, and as stars are often bright (and rare, 
Star  giving a high probability) but not often X-ray loud the source may be a 
Star  chance association.
Spec This source has a 2dF spectrum.
Z(a) Dubious redshift (see Sect. 4.4). 
Z(a)  COMBO-17 redshift is 1.4 but it may be 0.16. 
Z(b) Dubious redshift (see Sect.4). 
Z(b)  COMBO-17 redshift is 0.33, but ~0.16 is found spectroscopically.