Tags: postel



Monday, September 20th, 2021

An Idea from Computer Science That Can Change Your Life – Jorge Arango

Applying Postel’s Law to relationships:

I aspire to be conservative in what and how I share (i.e., avoid drama) while understanding that other people will say all sorts of unmindful things.

Wednesday, March 11th, 2020

A curl in every port

A few years back, Zach Bloom wrote The History of the URL: Path, Fragment, Query, and Auth. He recently expanded on it and republished it on the Cloudflare blog as The History of the URL. It’s well worth the time to read the whole thing. It’s packed full of fascinating tidbits.

In the section on ports, Zach says:

The timeline of Gopher and HTTP can be evidenced by their default port numbers. Gopher is 70, HTTP 80. The HTTP port was assigned (likely by Jon Postel at the IANA) at the request of Tim Berners-Lee sometime between 1990 and 1992.

Ooh, I can give you an exact date! It was January 24th, 1992. I know this because of the hack week in CERN last year to recreate the first ever web browser.

Kimberly was spelunking down the original source code, when she came across this line in the HTUtils.h file:

#define TCP_PORT 80 /* Allocated to http by Jon Postel/ISI 24-Jan-92 */

We showed this to Jean-François Groff, who worked on the original web technologies like libwww, the forerunner to libcurl. He remembers that day. It felt like they had “made it”, receiving the official blessing of Jon Postel (in the same RFC, incidentally, that gave port 70 to Gopher).

Then he told us something interesting about the next line of code:

#define OLD_TCP_PORT 2784 /* Try the old one if no answer on 80 */

Port 2784? That seems like an odd choice. Most of us would choose something easy to remember.

Well, it turns out that 2784 is easy to remember if you’re Tim Berners-Lee.

Those were the last four digits of his parents’ phone number.

Tuesday, May 17th, 2016

Design systems and Postel’s law | Journal | The Personal Disquiet of Mark Boulton

Marvellous insights from Mark on how the robustness principle can and should be applied to styeguides and pattern libraries (‘sfunny—I was talking about Postel’s Law just this morning at An Event Apart in Boston).

Being liberal in accepting things into the system, and being liberal about how you go about that, ensures you don’t police the system. You collaborate on it.

So, what about the output? Remember: be ’conservative in what you do’. For a design system, this means your output of the system – guidelines, principles, design patterns, code, etc etc. – needs to be clear, unambiguous, and understandable.

Thursday, April 23rd, 2015