Re: Port number in Link in HTML5

M@trixX wrote:

> Line 19, Column 41: Bad value http://petra.underald.net:270/ for
> attribute href on element a: PORT_SHOULD_NOT_BE_WELL_KNOWN in PORT.
> <a href="http://petra.underald.net:270/">Server</a><br>
>
> I didn't find WHY this should be error, so i think that something's
> bad in validator... Or I'm wrong?

It's not an error, and surely not a reportable markup error, which is what a 
validator should report. The W3C "Markup Validator" is more and more 
becoming a kludgy heuristic*) checker, a fairly obscure linter, especially 
when used to "validate" "HTML 5" documents.

This time it's obviously trying to say that port numbers in http URLs should 
obey some rules (which is something completely external to markup issues, 
comparable to whining about language style in text strings or about color 
choices). The half-cryptic message, which is labeled as an _error_ against 
all reason, seems to say that port numbers should not be "well known", 
apparently referring to documentation of "well known port numbers", 
http://www.iana.org/assignments/port-numbers

This is absurd, since it would mean that port numbers like 80 (the default 
for http URLs) and 8080 should not be used, since they are definitively 
"well known". So I would deduce that the error message says just the 
opposite of what its creators meant to say: port numbers _should be_ "well 
known".

This would be somewhat questionable as a warning and just grossly wrong as 
an error message. There is no reason to say, in a general-purpose checker, 
that unassigned port numbers (like 270) should not be used. For all that a 
checker can know, the document might be for private use in a private 
network, or an experimental document.

(And for all that a markup validator proper can know, 
"http://petra.underald.net:270/" is a string of characters that matches 
CDATA as attribute type and must not be reported as a markup error.)

*) "Heuristic" is Greek for "guesswork".

-- 
Yucca, http://www.cs.tut.fi/~jkorpela/

Received on Saturday, 30 May 2009 15:27:11 UTC