Will add a bullet to the Observation population rules that indicates "If the Observation selected for population is a Quantity with a comparator (e.g. "greater than", "less than", etc.) then that Observation cannot be used for population as the semantics of the comparator would be lost." Will add generic language for all extraction mechanisms that says "When selecting data for extraction, systems must always check for the presence of modifier elements or other elements (e.g. Quantity.comparator) that may shift the meaning of the data elements selected and ensure that records whose meaning might be atypical are either not used for extraction or are appropriately flagged to the user for review and possible adjustment."