All DDEX standards come in different versions. Over time, DDEX members and licensees have identified additional requirements that are then added into subsequent versions of a specific standard. DDEX standards are backwards compatible with few exceptions (see below). This means that, for instance:
- A message in version 3.2 of a specific standard will be able to be processed with no change by a processor for version 3.3; and
- A message in version 3.3 of a specific standard will be able to be processed with no change by a processor for version 3.2, provided that none of the new features of version 3.3 are being used or are important for either party.
There are two cases where messages in two versions may not be compatible to one another:
- If the major version number is different – for instance a DSR sales/usage report in version 3.2 cannot be read with a processor written for version 4.1.
- If a bug was fixed – for instance an ERN product message in version 3.4.1 may not be processable by a program written for version 3.4. Note: that such bug fixes typically only affect one small aspect and, thus, many application would still be able to process old files, and that any changes are usually small and, thus, updating the relevant code may well be comparatively simple.