- The First Substitute Always Repeats The Uppermost Signal Flag Of That Class Of Flags Which Immediately Preceeds The Substitute.
- The Use Of Substitutes Is To Enable The Same Signal Flag-Either Alphabetical Flag Or Numeral Pendant, To Be Repeated One Or More Times In The Same Group, In Case Only One Set Of Flags Is Carried On Board.
- The Second Substitute Always Repeats The Second, And The Third Substitute Repeats The Third Signal Flag, Counting From The Top Of That Class Of Flags Which Immediately Preceeds Them.
- No Substitute Can Ever Be Used More Than Once In The Same Group
CHAPTER 6: FLASHING LIGHT SIGNALLING
Signal Made By Flashing Light Is Divided Into The Foll Parts:
