In the latest version of EdiFabric Templates (220.127.116.11) there is a folder for the pre errata templates called HIPAA/005010/PreErrata. In order to support that version of the standard (for example, 005010X221) we copy that folder to a separate project treating it separately from the current version (for example, 005010X221A1). However, that folder PreErrata does not have the required interfaces. Could you please confirm that we should also copy the files EF_HIPAA_005010_SegmentInterfaces.cs and EF_HIPAA_005010_ComplexElementInterfaces.cs from the parent folder? Or do you have a better approach in mind with less cop/pasting? As frankly, due to the slight differences in the classes and properties names we had to copy all our code for each version. If there is a way to reuse some of them it would be better.