Version numbering conventions

[LinguaCelta]

How will we increment version numbers for future updates to the iXML spec? Should we consider distinguishing major and minor updates (e.g. according to whether changes are backward-incompatible)? If so, how? (For example, we could decide that a change from 1.0 > 1.1 represents a minor update, and from 1.1 > 2.0 represents a major update.)