It's been 20 years today (Oct 16, UTC). Hard to believe.

Tue Oct 16 18:10:31 UTC 2018

On Tue, Oct 16, 2018 at 02:01:48PM -0400, Daniel Corbe wrote:
> The one thing I remember about Postel, other than the fact that he had his  
> fingers in a lot of DNS pies, is be liberal about what you accept, be  
> conservative about what you send.  It’s a notion that creates undo burden  
> on the implementor, because it places the expectation on the that you need  
> to account for every conceivable ambiguous corner case and that’s not  
> always the best approach when implementing a standard; and it mostly arises  
> from the lack of adherence to the second part of that statement.

I think that his aphorism is simply a recognition that NO standard
can cover all cases that might arise when dealing with complex
matters, no matter how much thought went into it.  People are
fallible, and the standards they write are inevitably flawed in
some way, so a realistic implementor has to allow some slack or be
continually engaged in finger-pointing when something doesn't work.
	- Brian