**Table 5:** Published "white light'' polarization data for the verification objects.
Object	p_l	$\sigma_{p_l}$	$\theta _l$	$\sigma_{\theta_l}$	Ref.
	(%)	(%)	( $^{\circ }$ )	( $^{\circ }$ )
PG 0946+301	0.85	0.14	116	5	1, 2
PG 1004+130	0.79	0.11	77	4	2
PG 1012+008	0.66	0.23	98	10	2
PKS 1049-09	0.85	0.30	96	10	2
PG 1216+069	0.80	0.19	53	7	2
TON 1530	0.84	0.24	150	8	2
PG 1254+047	1.22	0.15	165	3	2, 1
PG 1435-067	1.44	0.29	27	6	2
2MA 1519+1838	0.67	0.22	132	11	3
2MA 1543+1937	1.33	0.26	30	6	3
3C 323.1	1.03	0.20	4	5	2
MARK 877	0.94	0.17	79	5	2
2MA J1714+2602	0.86	0.33	65	12	3

References: (1) Schmidt & Hines (1999); (2) Berriman et al. (1990); (3) Smith et al. (2002). When more than one measurement is available (cf. PG 0946+301 and PG 1254+047), the value with the smallest $\sigma_{p_l}$ is given.

Source LaTeX | All tables | In the text

	1 Introduction
	2 The observations
	3 Data reduction
	4 The results
	5 Conclusions
	References