A peak's line parent is the closest higher peak on the highest ridge leading away from the peak's "key col". A col is the lowest point on the ridge between two summits and is  synonymous with pass, gap, saddle and notch. A peak's "key col " is the lowest point on the ridge which connects the peak and a higher peak . If there is more than one ridge which can be followed to a higher peak then the line parent is the peak closest to the key col. Usually, a line parent must meet some prominence criteria, which might vary depending on the author and the location of the peak.
A peak's line parent is the closest higher peak on the highest ridge leading away from the peak's "key col". A col is the lowest point on the ridge between two summits and is roughly synonymous with pass, gap, saddle and notch. The highest col of a peak is its key col . If there is more than one ridge which can be followed to a higher peak then the line parent is the peak closest to the key col. Usually, a line parent must meet some prominence criteria, which might vary depending on the author and the location of the peak.
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A peak's "key col " is the lowest point on the ridge which connects the peak and a higher peak
The highest col of a peak is its key col