Reading the phrase
The first number is the window at full value. The second word describes what happens to the cover once that window closes: it begins to reduce across the remaining years of the term.
So the term is not shortened by the prorated part. A Fortify roof on Good still has a 15-year term; what changes is how much the cover is worth in year twelve compared with year two.
Where the full window is five years
Fortify carries hybrid cover with a five-year full window, on both bands where it is issued: 15 years on Good and 12 years on Fair. Those are the rows a roof that is still holding up will most often land in.
Fortify Elite also has a five-year figure, but in a different place: it is 5 years of hail coverage sitting on top of a 20-year non-prorated term, not a prorated window.
Where the full window is three years
Revive carries hybrid cover with a shorter full window on the lower bands: full value for the first three years, then prorated, for 7 years on Low or Critical.
On Aging, Revive carries the longer window: full value for the first five years, then prorated, across 10 years. The window shortens as the roof gets older, which is the same logic that shortens the term.
What it means when you claim
The practical difference shows up at the point of a claim, not on the day of application. A problem found while the full window is open is met at full value; the same problem found later is met on the reducing scale.
The remedy itself does not change: a free inspection first, then a free re-treatment where the inspection supports one, then a roofing material allowance if the re-treatment does not resolve it.
Where the term is quoted
The estimate names the row, and the row carries both numbers: the term and the shape of the cover. So a hybrid term is never quoted as a bare number of years, which is the mistake this distinction exists to prevent.