Please Stop Polluting

When I surf the web, I almost always have Fiddler running, and as a consequence I see a lot of “hidden” pollution in pages. Much of this cruft has built up over the years, copied from site to site, probably with little critical thought about its necessity.

Please remove any META tags you have that specify MSSmartTagsPreventParsing. This directive only ever had any effect in an IE6 Beta, and the feature in question never shipped in a final version of the browser. Sending this directive is a waste of bandwidth.

Next, META tags that specify imagetoolbar should probably be removed. This META disables the IE6-era Gallery Toolbar that showed atop images of a certain size; that toolbar was removed in IE7. Similarly, the galleryimg attribute on IMG tags is generally not needed for the same reason.

In nearly all cases, sites that send the pre-check and post-check directives in the Cache-Control HTTP Response header should remove these directives. These directives only ever worked in Desktop IE browsers, and they almost always are sent as part of a long string of no-cache directives (PHP unnecessarily sent these directives when a page was not to be cached). Sending these directives when you’re using other directives to forbid caching is a waste of bandwidth.


Comments (4)
  1. Julian Reschke says:

    Another favorite of mine is

     Content-Transfer-Encoding: binary

    which seems to be another useless PHPism.

  2. Billy Hoffman says:

    Thank you Eric for 5 new checks I should add to Zoompf's performance scanner!

    I also see sites using Meta tags/HTTP header which set "Content-Script-Type" "Content-Style-Type". This is wasteful as I know of no browser that actually uses these, and it breaks HTML5 validation.

  3. RichB says:

    These sort of rules would be great to add to developer tools – perhaps on something like webkit's audit tab.

  4. Mike says:

    Easy solution, just stop using this MSIE crap. It's cute you guys think you can develop a web browser, but really? Think again…

    – A Security Guy / Software Engineer

Comments are closed.

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