8. The method of claim 2 , wherein the rule file comprises a rule specifying a subset of one or more of the three versions of the structured data file as requiring uniqueness such that two or more modified data items with the same unique identifier are in conflict.
2. The method of claim 1 further comprising: identifying a rule file associated with the determined dialect; using the rule file, identifying different subsets of one or more of the three versions of the structured data file and at least one of different merge or diff rules associated with the different subsets of one or more of the three versions of the structured data file; and applying the different rules to the different subsets of one or more of the three versions of the structured data file.