When delegates collaborate on the repository identity, their voting narrows the tree of active proposals to the chain of accepted proposals. Thus, they crucially must understand which proposals are siblings, i.e., which proposals share the same parent, because no two sibling proposals should ever be accepted at the same time, as this would mean a fork.

To ease collaboration of delegates and improve their overview, also print the parent revision, if present. Note that the initial revision is the only revision that has no parent.