Linked from
The 15 pages that link to Carbon-14, each with the reason it gives.
IsotopeBroader topic: Its decay underpins a widely used method for dating once-living material.
CarbonBroader topic: Its decay makes carbon useful for dating once-living materials.
Mass numberBroader topic: Its mass number gives the total nucleons used in radiocarbon dating.
IsobarBroader topic: It beta-decays into nitrogen-14, an isobar.