送信するものに関しては厳密に、受信するものに関しては寛容に
be conservative in what you do, be liberal in what you accept from others.
自分の行動は厳密に、他人から受け入れることは寛容に (often reworded as "Be conservative in what you send, be liberal in what you accept").
送信するものに関しては厳密に、受信するものに関しては寛容に インターネットの原理に繋がる規範だから、この価値は古びない
もし、この規範がないがしろにされるのであれば、それはインターネットの脱インターネット化であるといえる
そうであるならば、最後まで戦うか、さっさとずらかるか
Postel's Law, XML and HTML5 kzys.icon
On the other hand, it’s painfully obvious that this law does have exceptions.
XML::Liberal is a super liberal XML parser that can fix broken XML stream and create a DOM node out of it.
The W3C saw this as a fundamental problem with the web, and they set out to correct it. XML, published in 1997, broke from the tradition of forgiving clients and mandated that all programs that consumed XML must treat so-called “well-formedness” errors as fatal.
Browsers have always been “forgiving” with HTML. If you create an HTML page but forget the </head> tag, browsers will display the page anyway. (Certain tags implicitly trigger the end of the <head> and the start of the <body>.) You are supposed to nest tags hierarchically — closing them in last-in-first-out order — but if you create markup like <b><i></b></i>, browsers will just deal with it (somehow) and move on without displaying an error message.
As you might expect, the fact that “broken” HTML markup still worked in web browsers led authors to create broken HTML pages. A lot of broken pages. By some estimates, over 99% of HTML pages on the web today have at least one error in them. But because these errors don’t cause browsers to display visible error messages, nobody ever fixes them.
nobody ever fixes them
「お客様は神様だ」を自分が考えて行動するのはトラブルにならず、他人が強制してくるのはトラブルになりやすいという非対称性に似ていないか思いをはせている