[rfc-i] On backwards compatibility for v2

Dave Crocker dhc at dcrocker.net
Mon Feb 10 14:15:56 PST 2014

On 2/10/2014 1:39 PM, Ted Lemon wrote:
> I suspect that the meat of your argument is that if the v3 format
> isn't backward compatible to v2, the tool won't necessarily work with
> all v2 documents.


 > But the move from v1 to v2 has already shown us
> that the even when the format isn't changing in major ways, different
> tools may interpret it differently, and bugs may arise.

Interoperability (compatibility) is difficult, so let's not try?

But mostly I think your citing v1/v2 serves to show the problem of not 
making compatibility a core requirement.

> This isn't something that can realistically be prevented without a
> lot more developmental rigor than I anticipate.

I'm not sure what sort of 'rigor' you think would be needed.

But has anyone else noticed the irony of such easy dismissal of backward 
compatibility being made over the Internet and with email?

At base, I think we're being quite cavalier about the actual costs of 


ps. In case my suggesting that there is irony doesn't resonate, I mean 
to point to 30+ years of compatible TCP/IP operation and nearly 40 years 
of nearly-compatible basic email messages, both in spite of massive and 
constant enhancements.

Dave Crocker
Brandenburg InternetWorking

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