Linked from
The 9 pages that link to Fortified wine, each with the reason it gives.
WineBroader topic: Port and sherry show how spirit addition creates distinct wine styles.
WinemakingBroader topic: Fortification changes alcohol, sweetness, and fermentation outcomes.
LiqueurCompared with: Fortified wine begins as wine, whereas liqueur begins with distilled spirits.
Marsala wineNarrower topic: Marsala’s defining production step is fortification with grape spirit.
Sparkling wineCompared with: Fortification raises alcohol; it does not define a wine by its bubbles.