0010+775  The optical spectrum and redshift is given in Stickel et al. (1993a). The redshift has also been listed by Xu et al. (1994).
0018+729  The identification and optical magnitude have been taken from Stanghellini et al. (1993a)
0036+744  The classification as an empty field (Kuhr et al. 1987) has been confirmed with a deeper CCD image (Stickel & Kuhr 1995)
0124+845  The tentative classification as a faint (m = 23.7 mag) galaxy is given in Stickel & Kuhr (1995).
0153+744  The optical brightness is given in Stickel & Kuhr (1995).
0201+796  The identification and classification of the optical counterpart as a m = 22.2 mag galaxy is given in Stickel & Kuhr (1995).
0205+722  The identification and classification of the optical counterpart as a m = 20.7 mag QSO is given in Stickel & Kuhr (1995). The identification listed by Taylor et al. (1994) is incorrect (see also Kuhr et al. 1987).
0223+774  The optical identification has also been given by Riley (1989).
0223+814  The tentative classification as a galaxy is given in Kuhr et al. (1987).
0238+711  The optical brightness is given in Stickel & Kuhr (1995). 
0251+785  The tentative classification as a QSO is given in Kuhr et al. (1987).
0258+772  The identification and classification of the optical counterpart as a m = 21.5 mag galaxy is given in Stickel & Kuhr (1995).
0328+740  The revised identification and optical magnitude as well as the optical spectrum and redshift were given in Stickel & Kuhr (1993b).
0346+800  The tentative classification as a QSO is given in Kuhr et al. (1987).
0403+768  The optical identification as a galaxy given by Peacock et al. (1981) has been confirmed with a deeper CCD image (Stickel & Kuhr 1995), from which the optical magnitude of m = 21.2 mag has been derived. The redshift has been listed by O'Dea et al. (1991).
0407+747  The redshift has been taken from Herbig & Readhead (1992). However, Xu et al. (1994) observed a featureless optical spectrum characteristic for a BL Lac object.
0415+763  The tentative identification as a galaxy (Kuhr et al. 1987) has been confirmed with a deeper CCD image (Stickel & Kuhr 1995), from which the optical magnitude of m = 21.9 mag has been derived.
0437+785  The optical brightness was taken from Stickel & Kuhr (1995). The optical spectrum and redshift have been given in Stickel et al. (1993a).
0440+732  The optical brightness has been taken from Stickel & Kuhr (1995). The optical spectrum and redshift have been given in Stickel et al. (1993a).
0454+844  The redshift of z = 0.112 has been made available to us by C. Lawrence (1993, priv. comm.). This value is in obvious contrast to the lower limit of z > 0.2 suggested in Stickel et al. (1993b) on the basis of the unresolved appearance on the direct image. This indicates that the host galaxy of this BL Lac object has an unusually low optical luminosity (see the discussion in Stickel et al. 1993b).
0518+705  The revised identification of the stronger radio component of 0518+705 with a faint (m = 20.0 mag) QSO lying only 1" west of a m = 18 mag galactic star has been given in Stickel & Kuhr (1993b).
0546+726  The redshift has been derived from a spectrum taken by one of us (H.K.) with the Steward Observatory 90" telescope.
0604+728  The identification and classification of the optical counterpart as a m = 20.3 mag QSO is given in Stickel & Kuhr (1995).
0615+820  The redshift listed by Eckart et al. (1986) is based on spectra taken by one of us (H.K.) with the Steward Observatory 90" telescope and the Multiple Mirror Telescope.
0625+842  The identification and classification of the optical counterpart as a m = 21.1 mag galaxy is given in Stickel & Kuhr (1995). 
0633+734  The confirmed identification and classificattion of the optical counterpart as a m = 18.2 quasar is given in Stickel & Kuhr (1995). The redshift has been derived from a spectrum taken by one (H.K.) with the Steward Observatory 90" telescope.
0647+733  Although no optical counterpart has found exactly at the radio position, the Head-Tail radio structure (Kuhr et al. 1987) suggests that one of the galaxies detected around the radio position is the correct optical identification (Stickel & Kuhr 1915)
0740+767  The tentative classification as a galaxy is given in Kuhr et al. (1987). The optical magnitude has been taken from Kuhr (1980).
0740+828  The optical brightness has been taken Stickel & Kuhr (1995). The optical identification has also been given by Riley (1989). The redshift has been taken from Xu et al. (1994). The single emission redshift given in Stickel et al. (1993a) and listed in Veron-Cetty & Veron (1993) is incorrect.
0743+744  This radio source lies close to the galaxy Mkn 11 and the identification with a QSO has been made by Condon & Broderick (1988). The optical spectrum and redshift is given in Stickel et al. (1993a).
0819+770  The optical brightness has been taken from Stickel & Kuhr (1995). The optical spectrum and redshift have been given in Stickel et al. (1993a).
0820+742  The identification and classification of the optical counterpart as a m = 20.9 mag galaxy is in Stickel & Kuhr (1995).
0824+802  The identification and classification of the optical counterpart as a m = 21.3 mag galaxy is in Stickel & Kuhr (1995).
0836+710  The optical spectrum and redshift is given in Stickel & Kuhr (1993a). The redshift has previously been listed by Eckart et al. (1986), based on spetra taken by one of us (H.K.) with the Steward Observatory 90" telescope and the Multiple Mirror Telescope.
0916+718  The redshift has been derived from spectra taken by one of us (H.K.) with the Steward Obervatory 90" telescope and the Multiple Mirror Telescope
0925+745  The classification as an empty field is given in Stickel & Kuhr (1995). The faint optical couterpart proposed in Kuhr et al. (1987) could not be confirmed
0926+793  The redshift has been taken from McCarthy (1988).
0936+831  The identification and classification of the optical counterpart as a m = 19.9 mag galaxy is given in Stickel & Kuhr (1995).
0950+748  The identification and classification of the optical counterpart as a m = 21.7 mag galaxy is given in Stickel & Kuhr (1995).
1003+830  The redshift has been taken from Xu el al. (1994).
1004+861  The confirmed identification and classification of the optical counterpart as a m = 17.5 mag galaxy is given in Stickel & Kuhr (1995). The optical spectrum and redshift of the optical counterpart have been given in Stickel et al. (1993a).
1007+716  The optical spectrum and redshift of the optical counterpart have been given in Stickel et al. (1993a) .
1009+748  The confirmed identification and classification of the optical counterpart as a m = 20.9 mag galaxy is given in Stickel & Kuhr (1995).
1018+807  The optical identification has also been given by Riley (1989).
1027+749  The confirmed identification and classification of the optical counterpart as a galaxy with a possible point source in its center is given in Stickel & Kuhr (1995). The optical spectrum and redshift have been given in Stickel & Kuhr (1993a).
1039+811  The redshift is derived from a spectrum taken by one of us (H.K.) with the Steward Observatory 90" telescope and has previously been listed by Eckart et al. (1986).
1042+736  The optical spectrum and redshift have been given in Stickel & Kuhr (1993a).
1044+719  The identification and classification of the optical counterpart as a m = 17.8 mag QSO is given in Stickel & Kuhr (1995). The redshift has been listed by Poladitis et al. (1995).
1053+704  The redshift has been derived from a spectrum taken by one of us (H.K.) with the Steward Observatory 90" telescope. The redshift has also been listed by Xu et al. (1994).
1053+815  The classification of 1053+815 as a quasar rather than a galaxy (as listed in Kuhr et al. 1987) is based on the observed emission lines (z = 0.706, Xu et al. 1994). The optical brightnesses listed in Kuhr et al. (1987) and Kuhr & Schmidt (1990) indicate optical variability of a least one magnitude.
1058+726  The redshift has been taken from Veron Cetty & Veron (1993). The redshift listed in Kuhr et al. (1987) is incorrect.
1100+798  The identification and classification of the optical counterpart as a m = 20.4 mag galaxy is given in Stickel & Kuhr (1995).
1142+702  The classification as an empty field is given in Stickel & Kuhr (1995). The faint optical couterpart proposed in Kuhr et al. (1987) could not be confirmed.
1150+812  The redshift is derived from spectra taken by one of us (H.K.) with Steward Observatory 90" telescope and has previously been listed by Eckart et al. (1986).
1152+758  The identification and classification of the optical counterpart as a m = 21.6 mag galaxy is given in Stickel & Kuhr (1995).
1217+713  The redshift has been derived from a spectrum taken by one of us (H.K.) with the Steward Observatory 90" telescope.
1236+842  The optical spectrum and redshift have been given in Stickel & Kuhr (1994b). The optical brightness of m = 18.9 listed in Table 1 has been derived from the CCD image given there.
1241+735  The radio position listed in Kuhr et al. (1987) is incorrect and superseded by that given in Patnaik et al. (1992). The optical counterpart of 1241+735 is a bright, m = 17 mag galaxy (Stickel & Kuhr 1995), member of a small group of galaxies (see finding chart in Kuhr et al. 1987).
1259+811  The identification and classification of the optical counterpart as a m = 22.3 mag galaxy is given in Stickel & Kuhr (1995).
1322+835  The classification as an empty field is given in Stickel & Kuhr (1995). The faint optical counterpart proposed by Kuhr et al. (1987) could not be confirmed.
1323+799  The tentative classification of the optical counterpart as a m = 21.5 mag galaxy is given in Stickel & Kuhr (1995).
1345+736  The optical spectrum and redshift have been given in Stickel & Kuhr (1994b).
1436+763  The tentative classification as a QSO is given in Kuhr et al. (1987).
1448+762  The identification with a faint object (m = 22.3 mag) is given in Stickel & Kuhr (1995). The classification as a QSO is based on the observed emission line spectrum at z = 0.899 (Vermeulen & Taylor 1995).
1520+725  The optical identification has also been given by Riley (1989). The optical spectrum and redshift have been given in Stickel & Kuhr (1994b).
1531+722  The optical spectrum and redshift have been given in Stickel et al. (1993). The optical brightness has been taken from Stickel & Kuhr (1995). The quasar lies only 4" away from the center of a foreground galaxy (z = 0.102), which itself is possibly member of a foreground galaxy group (see CCD im age in Stickel & Kuhr 1995).
1557+708  The optical spectrum and redshift was given in Stickel et al. (1993a). The redshift has also been listed by Herbig & Readhead (1992) and Xu et al. (1994). Because no radio flux and spectral index ware tabulated in the original S5 catalogue (Kuhr et al. 1981b), these values have been taken from the S4 catalogue (Pauliny-Toth et al. 1978)
1616+851  The revised classification as a m = 17.4 mag galaxy as well as the optical spectrum and the redshift have been given in Stickel & Kuhr (1993a).
1635+742  The tentative classification of the optical counterpart as a m = 22.9 mag galaxy is given in Stickel & Kuhr (1995).
1650+758  The identification and classification of the optical counterpart as a m = 19.2 mag galaxy is given in Stickel & Kuhr (1995).
1726+769  The optical spectrum and redshift have been given in Stickel & Kuhr (1994b).
1733+714  The optical spectrum and redshift have been given in Stickel et al. (1993a).
1746+712  The optical spectrum and redshift have been given in Stickel & Kuhr (1994b).
1749+701  Since the flux density and spectral index had not been listed in the original S5 catalogue (Kuh et al. 1981b), these values have been taken from the updated 1 Jy catalogue (Stickel et al. 1994).
1811+738  The identification and classification of the optical counterpart as a m = 20.1 mag galaxy is given in Stickel & Kuhr (1995).
1826+796  The redshift has been derived from a spectrum taken by one of us (H.K.) with the Steward Observatory 90" telescope.
1856+737  The optical spectrum and redshift have been given in Stickel & Kuhr (1994b). The entry fo 1856+737 in the catalogue of Veron-Cetty & Veron (1993) has an incorrect object name.
1914+855  The identification and classification of the optical counterpart as a m = 21.1 mag galaxy is given in Stickel & Kuhr (1995).
1920+744  The identification and classification of thf optical counterpart as a m = 21.6 mag galaxy is given in Stickel & Kuhr (1995).
1928+738  The redshift listed in Kuhr et al. (1987) is incorrect. The correct redshift is given in Lawrence el al. (1986) and Stickel et al. (1993a).
1936+714  The optical spectrum and redshift have been given in Stickel et al. (1993a).
1939+813  The identification and classification of the optical counterpart as a m = 21.1 mag galaxy is given in Stickel & Kuhr (1995).
2010+723  The classification as a BL Lac object is based on featureless spectra observed by Stickel & Kuhr (1993b) and Xu et al. (1994). The optical brightness has been taken from Stickel & Kuhr (1995). The optical counterpart is unresolved, suggesting a lower redshift limit of of z > 0.2 (Stickel & Kuhr 1995).
2017+745  The redshift has been derived from a spectrum taken by one of us (H.K.) with the Steward Observatory 90" telescope.
2018+732  The identification and classification of the optical counterpart as a m = 21.1 mag galaxy is given in Stickel & Kuhr (1995).
2023+760  The optical brightness has been taken fron Stickel & Kuhr (1995). The classification as a BL Lac object is based on a featureless spectrum (Stickel et al 1993). The optical counterpart is unresolved, suggesting a lower redshift limit of z > 0.2 (Stickel & Kuhr 1995).
2051+745  The optical brightness has been taken fron Stickel & Kuhr (1995).
2104+763  The identification, optical magnitude, and redshift have been taken from Smith et al. (1976).
2116+818  The optical spectrum and redshift has been given in Stickel et al. (1993a).
2118+749  The classification as an empty field (Kuhr et al. 1987) has been confirmed with a deeper CCD image (Stickel & Kuhr 1995).
2120+717  The identification and classification of the optical counterpart as a m = 20.2 mag galaxy is given in Stickel & Kuhr (1995).
2133+837  The identification and optical magnitude have been taken from Kristian et al. (1978).
2136+824  The confirmed identification and classification of the optical counterpart as a m = 19.6 QSO is given in Stickel & Kuhr (1995). The redshift has been derived from a spectrum taken by one of us (H.K) with the Steward Observatory 90" telescope.
2205+743  The identification and classification of the optical counterpart as a m = 22.5 mag galaxy is given in Stickel & Kuhr (1995).
2248+712  The identification, magnitude, and redshift have been taken from Djorgovski et al. (1988).
2325+822  The identification and classification of the optical counterpart as a m = 21.1 mag galaxy is given in Stickel & Kuhr (1995).
2342+821  The optical brightness has been taken from Stickel & Kuhr (1995).
2353+816  The classification as a BL Lac object is based on a featureless spectra. The optical counterpart is unresolved, suggesting a lower redshift limit of z > 0.2 (Stickel & Kuhr 1993b).