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

[Paul Eggert]

On 11/9/21 10:43, Stephen Colebourne via tz wrote:
> I'd be interested in your view as to how to group the IDs.

These groupings should provide useful information downstream. Perhaps 
something like the following:


* primary - These name the primary location of a region with clocks the 
same since 1970, e.g., Europe/London, Asia/Kolkata, Asia/Calcutta, 
Asia/Singapore, Singapore.

* secondary - These name secondary locations in a region, and exist only 
for compatibility with older tzdb versions, e.g., Australia/Canberra, 
Antarctica/South_Pole.

* posixish - These are for platforms that lack support for POSIX TZ 
settings, e.g., Etc/GMT, Greenwich, CET, EST5EDT, Zulu.

* obsolescent - These are planned to be removed in future releases. We 
could put "W-SU" into this category as an example, since the Soviet 
Union hasn't existed for decades. Other names could be moved into this 
category as they become obsolescent.

* other - These names don't fit into the above categories, and also 
exist only for compatibility with older tzdb versions, e.g., Cuba, 
Egypt, GB-Eire, Iceland, Navajo, PRC.


The above groupings don't worry about whether names are Zones or Links 
because that information is already present in the source code.