The mif schema files were downloaded from http://gforge.hl7.org/gf/project/mif-schemas/frs/?action=FrsReleaseBrowse&frs_package_id=14 - specifically, 
http://gforge.hl7.org/gf/download/frsrelease/603/6640/hl7_mifschemas-2.1.6.0.zip

In theory, this is version 2.1.6 of the schema, which is the closest that I can find to the schema version documented in the content files I'm processing 
(which specify 2.1.7)
