W3C home > Mailing lists > Public > www-validator@w3.org > March 2005

Re: Symantecs ad remover removes valid-xhtml image

From: Jukka K. Korpela <jkorpela@cs.tut.fi>
Date: Sat, 26 Mar 2005 09:21:41 +0200 (EET)
To: www-validator@w3.org
Cc: Peter Albertsson <Peter.Albertsson@spray.se>
Message-ID: <Pine.GSO.4.58.0503260905480.7435@korppi.cs.tut.fi>

On Sat, 26 Mar 2005, olivier Thereaux wrote:

> The "valid" icons aren't ads, so if this tool removes them as such,
> it's broken, and unfortunately there's little we can do about it.

Whether they are ads depends on the definition of "ad". Usually the
word "ad" refers to something that promotes a product or service that one
has to pay for, but it can be used in a broader sense as well, to refer
to anything promotional. On the Internet, the line between commercial and
"free" services is often vague, since so many "free" services are second-class
versions of paid services, or will later be turned to commercial
services (perhaps gradually), or exist for the purpose of making a
company known, so they are meant to attract paying customers. Even the
W3C, a consortium with membership fees, might be said to try to attract
new members by its provision of free services, which are advertized with
the icons.

Note in particular that the rules for using the icons require that the
icon be made a link to the service. This is typical of promotional icons
related to "free" services. Another typical feature is that the src
attribute refers to another site (though people _might_ use copies of
their own, and this might even be explicitly permitted). Yet another
feature is that the image is a link that refers to another site,
typically the same as that of the image.

On the technical side, if the image dimensions are those of typical ads,
it's no wonder that an ad blocking program filters them out. After all,
such programs do not inspect the content and purpose of an image; they
analyze its simple properties and apply so-called heuristics.

The heuristics can be fairly simplistic, so that they perhaps inspect only
the width and height attributes in HTML to determine the image's size,
not anything set in CSS, still less the actual image's properties.

I haven't studied whether the dimensions are in fact typical in that
sense. But if they are, then changing the dimensions might affect the
situation. Maybe even omitting the width and height attributes might
matter. I'm not saying you should do so, but technically, there are
things you _could_ do if you wish to increase the visibility of the icons.

Jukka "Yucca" Korpela, http://www.cs.tut.fi/~jkorpela/
Received on Saturday, 26 March 2005 07:22:15 UTC

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