Accuracy is one of the most important aspects of contesting today.
The operator skill in copying callsigns will have a profund impact in the final score. The level of log cross checking is higher than ever (around 60%). My advice is - if you are not absolutly sure about a callsign, don't log it, ask for a confirmation - if this is not your practice, the probability of being cross checked as a not in log and the probability of being marked as a bad callsign is very high.

For each not in log or bad callsigns, contact point and multiplier credit is denied. In addition, a point penalty of 3 times the claimed contact point value is computed, i.e. you loose the QSO plus the equivalent in points of 3 more QSO's.

The CQWW generates a UBN (uniques, bad and not in log) report to every entrant in the contest.
Click here for a guide to CQWW DX-Contest UBN and NIL reports.

In 2003 I won the SOAB category and broke the SA record and the all time CW SOAB QSO record. The result of log checking by the Contest Committee was the following:

Band	QSOs	Cross Checked	Bad Callsigns	Not in Log Callsigns	Multipliers Lost
160	344	219	0	1	1
80	715	503	7	3	2
40	1713	989	22	8	1
20	1437	851	11	7	0
15	1819	1078	19	6	0
10	1910	1077	17	9	0
Total	7938	4717	76	34	4
		59,4%	1,0%	0,4%

This the final result of my accuracy and the impact of log checking in my score:

	Points	QSOs	Zones	Countries
Claimed result	16,981,342	7938	169	550
Final result	15,943,070	7828	169	546
	-6,1%	-1,4%

Click here for P40E 2003 UBN report.
Remember - if not sure, don't log a callsign, ask for a confirmation.