a Optical counterpart falls just outside the strict search area (see Section 5
a  and Table 3).
b Identification from the Guide Star Catalog II, McLean et al. (2000) 
b  or VIZIER database.
c Identification from the Einstein Observatory Extended Medium-Sensitivity 
c  Survey, Stocke et al. (1991, Cat. <IX/15>), object MS1214.3+3811.
d Cataclysmic variable, spectrum shows a blueshift.
e Member of (non-target) nearby galaxy, NGC 5879.
f This object was identified using its 2-D spectrum as it could not be easily 
f  extracted to form a 1-D spectrum; the observable wavelength range is thus 
f  omitted.
g In Paper II (Eckart et al., 2005, Cat. <J/ApJS/156/35>) this source had 
g  optflag=5 (>1 optical source in the search area). Our spectrum shows a BLAGN,
g  thus we have changed the source to optflag=1, a secure optical counterpart 
   identification.
h Confirmed target cluster member (within 1Mpc of target cluster center).
i Confirmed (non-target) group/cluster detected in Holden et al.,
i  2002AJ....124...33H (see Section 11).
j Possible BALQSO.
k Line identification/ redshift tentative.
l This source spectrum shows two ELG, one at z=0.426, one at z=1.432. The nearer
l  source matches the R=22.25 in our photometry, but the fainter z=1.432 source,
l  undetected in our photometry, also appears in the error circle. This source 
l  is thus eliminated from our analysis.
m J145215.6+430448: low-ionization, broad absorption line quasar.
n Spectrum has gap of >100{AA} between red and blue side.