The identity matching refers to only the first and last name, which implies that patient's current name.  By not including previous names (which also includes variations of the names) in the guide, you might be limiting the number of good matches that the specs will support.  Patient names change and can be stored in different ways in different systems. It is common for one patient record to have a more updated version of the name - particularly when comparing data between systems.  While both systems might think they have the most up-to-date version of the name, that is not usually the case. For example, if a patient was recently married and changed their last name, when the patient is next seen, their name will be updated to their current name. However, another health system across town will still know the patient by their previous name. Using the framework described in this document, those two records would not be found as matches.  If the current health system also sends along a previous name, then they could establish a match.