At times, I was wondering why would an author link to an invalid site in their new article. It could be caused by typing mistakes but the author should always try to click on their own link before they publish the article.
I found one common mistake that lots of people would make. Google has a
goodbad example on this.
At this What is Web History? help page, if you point to the link in the page (refer the following image), you will see a weird link at status bar.
What I saw in status bar:
If the author used the following code to link, he will get the problem.
The author should include "http://" to avoid the problem.
So, web programmers, take note about this!