Dear Wilhelmina, short answer would be yes (for 3.x), so 3.4 was designed to be backwards compatible to 3.3, 3.5 should be backwards compatible to 3.4, etc. The MODS Editorial Committee has currently no plans to move to a 4.0 version that would introduce changes that could invalidate current MODS records. There is, however, a 3.7 version coming up and we will send out the approved changes for comment shortly. Best regards, Melanie Wacker Melanie Wacker Metadata Coordinator Original and Special Materials Cataloging Columbia University Libraries New York, N.Y. (212) 854 9676 On Mon, Apr 24, 2017 at 11:06 AM, Wilhelmina Randtke <[log in to unmask]> wrote: > Is MODS guaranteed to always be backwards compatible? > > > > Are all past releases backwards compatible? And will all future releases > be backwards compatible at least to MODS 3.4? > > > > Wilhelmina Randtke > > Digital Library Services Coordinator > > Florida Academic Library Services Cooperative > > Florida Virtual Campus > > Gainesville, FL 32606 > > (352) 415-6848 >