[tz] Proposal: Sections for different kinds of backward links

[Stephen Colebourne]

On Tue, 16 Nov 2021 at 18:20, Paul Eggert <eggert at cs.ucla.edu> wrote:
> On 11/14/21 15:16, Stephen Colebourne via tz wrote:
> > (If there is a spelling change in `secondary`, there is no mechanism
> > to determine which is the preferred spelling, as both IDs will Link to
> > the same primary ID.)
>
> I was thinking that one can look in zone.tab. If the spelling is there
> it's "preferred" otherwise it's not. This heuristic won't suffice for
> arbitrary questions about "preference" (as it doesn't impose a total
> order on names) but it should be good enough for questions relating to
> backward compatibility with older guidelines.

That makes these categories less useful. It involves a downstream
consumer processing zone.tab and cross-checking it. It also doesn't
handle the case where there is a spelling change for an ID that is not
listed in zone.tab.

It is not at all clear why you would want the `primary` category to
contain both Asia/Kolkata and Asia/Calcutta.

Stephen