Hyppigheder defineres som: meget almindelig (≥ 1/ 10); almindelig (≥ 1/ 100, < 1/ 10); ikke almindelig (≥ 1/ 1000, < 1/ 100); sjælden (≥ 1/ 10. 000, < 1/ 1000); meget sjælden (< 1/ 10. 000).
Frequencies are defined as: very common (≥ 1/ 10), common (≥ 1/ 100, < 1/ 10); uncommon (≥ 1/ 1,000, < 1/ 100); rare (≥ 1/ 10,000, < 1/ 1,000); very rare (< 1/ 10,000).