To qualify for inclusion a peak must also meet the more technical criterion of topographic prominence important in the mountaineering sport of peak-bagging.
A topographic prominence criterion is applied to exclude high points which are considered subsidiary peaks of a larger mountain.
The definition of topographic prominence is the vertical separation between a peak and the low point of the highest ridge connecting it to a higher one.
[citation needed] A committee of the Appalachian Mountain Club (AMC) sets the criteria and collects information verifying that peaks meet them.
It also maintains a list of the Four Thousand Footer Club's self-declared members, who request recognition for having ascended on foot all of the 48.