Hyppigheder defineres som: meget almindelig (≥ 1/ 10), almindelig (≥ 1/ 100 < 1/ 10), usædvanlig (≥ 1/ 1. 000 < 1/ 100).
Frequencies are defined as: very common (≥ 1/ 10), common (≥ 1/ 100 < 1/ 10), uncommon (≥ 1/ 1,000 < 1/ 100).