Prevent Robots from indexing portions of content

Yahoo! initially introduced a CSS class that can be used to notify robots/spiders that a specific section or fragment of content should not be included for search purposes.



Masquerading browser User-Agent strings

As it’s Halloween, it’s only relevant that I share a method of covering your browsers identity.

  • For MSIE, you must modify the registry. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\User Agent]
  • For Chrome (on Windows, and I assume other OS’s), you can use a startup parameter.
    C:\Users\{USERID}\AppData\Local\Google\Chrome\Application\chrome.exe --user-agent="Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_7_0; en-us) AppleWebKit/533.21.1 (KHTML, like Gecko) Version/5.0.5 Safari/533.21.1"
  • For Firefox and other Mozilla based browsers, you can mofiy the configuration in (user.js) or use a variety of add-on extensions, such as:

Interested in knowing your current User-Agent, just visit one of the following:

Many robots and spiders that are used by search engines also identify themselves by their User-Agent, if you see this activity in your logs you can often learn more about it at:


Happy Halloween!


SEO is always a tricky matter as it’s always changing, way back in 2007 Yahoo! added a means to ‘hide’ specific content on your page from it’s spider with the user of a CSS class that can be used anywhere on your page. True…. this can be abused, but is generally good to keep common content such as navigation and/or ads out of the index. Unfortunately, only Yahoo! supports this.