Retaining old file structure when editing in new version?

. Is it possible for me to make version 1.6.1 save in a way which retains compatibility with the older version? Thanks David Russell

Retaining old file structure when editing in new version?

. Is it possible for me to make version 1.6.1 save in a way which retains compatibility with the older version? Thanks David Russell

Retaining old file structure when editing in new version?

. Is it possible for me to make version 1.6.1 save in a way which retains compatibility with the older version? Thanks David Russell