For a fuse using a replaceable fuse link, Test Series 4 uses tests at two values of current It1 and It2, higher and lower currents than a "transfer current". The definition of which is the higher and which the lower is not consistent in 9.2.2.2.3, due to the transposition of the two terms in one location. In addition, after experience has been gained in performing testing as specified in 9.2.2.2.3 and Table 5, it has been found that, particularly for certain designs of fuse, additional clarification of the procedures to be used and modification to the testing would be helpful, and in some cases necessary, to achieve the desired results. Modification of 9.2.2.2.3 is therefore proposed. It has also been found that the wording of 18.1.1.3 may be ambiguous, leading to more than one method of performing the tests. This will be clarified.