Thus, although it is not traceable in the Signal Book, it was really reintroduced in Howe's third code.

This is clear from the last article of the Explanatory Instructions of 1799 which distinguishes between the two manoeuvres; but whether or not this article was in the Instructions of 1790 we cannot tell.

The probability is that it was not, for in the Signal Book of 1790 there is no reference to a modifying instruction.
Further, we know that in the code proposed by Sir Charles H.Knowles the only signal for breaking the line was word for word the same as Howe's.

This code he drew up in its final form in 1794, but it was not printed till 1798.

The presumption is therefore that until the code of 1799 was issued Howe's method of breaking the line was the only one recognised.