>And whatever you otherwise think about those languages, none of them will just make shit up when there is a syntax error in your program, they will simply reject it. And no, that does not mean that I am claiming that noone has ever made a syntactical mistake when writing code in those languages. But, you know, people are actually capable of fixing those mistakes when they are pointed out to them.

Except its pretty common now for programming languages add quality of life changes that loosen some of the strict parsing rules, such as trailing commas or optional semi colons. Same with whitespace, many languages don't pay much attention to it then you have a formatter that is strict about it (gofmt). This is Postels law in action, liberal acceptance strict output. The alternative is strict adherence to whitespace then no need for a formatter, just have the compiler reject it and put the burden on the programmer.

>Also, obviously, the "robustness principle" did not allow for a graceful update to the spec.

Again your opinion is not shared historically, ECN is held up as an example of the robustness principle having been followed in most stacks, with some problem ones that did not causing some issues [1].

>Then your points are just irrelevant?

Then your points are just irrelevant? We can play this game forever. Just the fact the you are using HTML and not XHTML and TCP under that to write these should make some relevant point that you can't seem to see.

>Yes, it was obvious that XHTML would fail due to the massive incompetence of developers ... your point being?!

Or more likely all these developers weren't incompetent including myself, just when given the choice the strictness of XHTML lost to the liberalness of HTML proving Postels law again. Messy and robust won over clean and fragile again, that's the point, get it?

>I am not sure what kind of game you are playing, but I had the impression like you were trying to make a point and not just state the historical fact that that's where Postel formulated the "robustness principle". Yeah, I agree, that's what he did. And it was a bad idea.

>As for TCP ... how is it relevant that Postel wrote the spec? Does that mean that the vulnerabilities in TCP never happened? Or are you saying that modern TCP implementations try to accept any crap whatsoever? (No, they don't, of course they don't, people have actually learned that that's a bad idea.)

Going back to you original question since your having hard time connecting the dots, Postel wrote the spec for TCP and put his law in the spec as guidance. ECN was developed taking advantage of that principle and most stacks accepted the malformed packets because of it. There are other examples of this [2], TCP is complicated if stacks didn't follow Postels law they would never get anything done on the internet.

1. https://tools.ietf.org/html/draft-ietf-tcpm-generalized-ecn-... 2. https://www.snellman.net/blog/archive/2016-02-01-tcp-rst/