7.2 Weight formulae. In record linkage the agreement weight of a particular comparison often depends highly on whether the name is common (lower weight) or rare (higher weight) (cf. RLiG §2-3, ¶¶ 3-3.8ff., 4-4.7, and §4-6). This difference may approach the difference between comparisons where the data is absent (zero weight) or present (unadjusted field weight). An agreement weight is indirectly proportional to the relative frequency of occurrence of the specific value in the field and directly proportional to the reliability (cf. RLiG equation 2.12). The disagreement weight is proportional to the complements of these two fractions (cf. RLS equation 2.13).