See comment above; maybe it is better to have this in the redmine issue tracking the ARM? The "target version" will be unknown for quite some time as the proposal is worked on; it is only possible to determine after a decision is made (it is then it is decided what will be done, by when etc. and the work is then going to be tracked in redmine). i.e. it is an attribute of the work that follows, not the ARM proposal.

However - one piece of metadata that is of interest is if the proposals impact on semver; essentially is it backwards compatible or not.