Issue link: http://itf.uberflip.com/i/450983
19 1.6 Conditions for ITF Approval All manufacturers that wish their ball brand(s) to be considered for inclusion on the list of ITF Approved tennis balls must submit a sample of such brand(s) for testing by the ITF in the manner described above. The sample of balls submitted must conform to the Rules of Tennis in all respects in order for ITF Approval to be granted. A ball which is granted ITF Approval is approved by the ITF only on the basis that it has been found to conform to the current Rules of Tennis and is therefore considered suitable for use in tournaments played according to the Rules of Tennis. ITF Approval does not imply any other form of approval. The ITF reserves the right to withdraw ITF Approval from any tennis ball brand(s) at any time if it finds that balls are substantially different from the sample(s) submitted for approval or, in the opinion of the ITF Technical Commission, such balls are not designed to meet the specification laid down in the Rules of Tennis, or if the approved balls otherwise fail to meet a reasonable quality standard. 1.7 Market and tournament testing The ITF has additional specific requirements for tennis balls which have been granted ITF Approval, to ensure that such balls continue to meet the standards laid down in the Rules of Tennis. Such balls may be obtained and tested from any source world- wide at the sole discretion of the ITF. ITF Approved balls are required to meet certain criteria, as described below, in order to retain ITF Approved status. The minimum sample size for balls tested under this procedure is 12. A ball which fails to conform to one or more of the specifications laid down in the Rules of Tennis will be counted as a single failure. The criteria by which samples of balls will be assessed are as follows: No. of balls in sample No. of balls failing to conform Action 12 0-1 2-3 4 + None Letter of warning 1 point towards removal of ITF Approval 24 0-2 3-7 8 + None Letter of warning 2 points towards removal of ITF Approval The above criteria are based on the normal distribution curve with action being taken in the form of either a warning letter to the manufacturer/distributor, or points towards