propagated data data that did not originally appear in a record, but which has been added to make linkage work (e.g., a date of birth may be p. d. so that this field will always be present (thus have a high merit ratio) and can be used in blocking); p. d. may also be original but redundant and harmful to record linkage, as when "Mary Brown" is entered as "Mrs. John Smith"; p. d. usually depend on rules requiring the presence of certain other data (cf. virtual event) [Cf. RLG Chapter 1, §6]