This type of code needs to refer to a specific piece of text, for instance the first page of your Scout handbook, or the front page article on today's newspaper. Each triple of numbers gives which number paragraph, word and letter to use.
For instance, if this explanation is used to solve the code, 1.3.2 would mean the first paragraph (above) third word (of) second letter (F). And 2.5.1 would refer to the second paragraph (this one), 5th word (used), first letter (U).
Once you're started, it's easy:
1.5.5 2.2.7 1.4.2 2.8.2 1.1.1
Sometimes the code will refer to whole words instead of letters:
1.1 1.4 2.6 1.9 3.5 = "This code is easy"