Notes on backwards compatibility

The DITA TC has determined that changes for DITA 1.1 should be backwards compatible with DITA 1.0. The following items are a guide to what is or is not considered backwards compatible.

For OASIS DITA 1.1, backwards compatible means that changes must be compatible with all preexisting documents written under DITA 1.0. Changes for DITA 1.1 do not have to be backwards compatible with vendor implementations of DITA 1.0.

Backwards compatible changes

The following changes are all backwards compatible, though the list is not considered exhaustive. The TC has not announced any preference for one type of change over another.

Backwards incompatible changes

The following changes are all considered backwards incompatible, and should be avoided for DITA 1.1.

Compatibility with the DITA architecture

In addition to backwards compatibility, any change must be tested to ensure it does not break other aspects of the DITA architecture. Two aspects of the architecture that should be tested first are conref and generalization. These are picked not because they are more important, but because they are typically the first to break due to an incorrect design. Michael Priestley put together a use case document that describes how to test for compatibility with these; the document is located here: http://lists.oasis-open.org/archives/dita/200506/msg00024.html