[TedDoesntTalk]

> bad advice ... being liberal in what you accept causes even more malformed data to appear in the ecosystem.

This is one perspective. Another is to be robust and resilient. Resiliency is a hallmark of good engineering. I get the sense you have not worked on server-side software that has thousands or millions of different clients.

[SAI_Peregrinus]

Postel's Law should be called the "Hardness Principle", not the "Robustness Principle". Much like how hardening a metal makes it take more force to break, but results in it being brittle & failing catastrophically when it does, so Postel's law makes systems harder to break initially, but results in more damage when they do fail. It also makes the system harder to maintain, thus adding a pun to the name.

[dns_snek]

Where do you draw the line? Usually there's exactly 1 intended, standard way of communicating with another system while there's are infinite opportunities to deviate from that standard and infinite opportunities for the other party to try to guess what you really meant. This results in a combinatorial explosion unintended behaviors that lead to bugs and critical security vulnerabilities.

[chowells]

I absolutely have. And I've never modified a server to accept bullshit from an incorrect client. I have, on the other hand, told several people how to fix their clients when they complain it doesn't work with my service. I actually rather enjoy improving the ecosystem, even if it's not strictly my job. It's better for everyone.