Commentary on top 10 blog usability mistakes - links don't say where they go

Fourth usability mistake in to the top 10 blog usability mistakes by Jakob Nielsen (2005) is having nondescript links in blog post, like this. This type of usability problem is also common in normal web pages where users have to guess where the links are going or try to find out the destinations with trial and error. There should also be clear difference between internal and external links so that user knows if clicking the link will take them into another post in the same blog or if it will take them in completely different site. Also there should be clear (usually color) difference between visited and unvisited links so that users don't have to remember which links they have already visited. Some authors have the external links to open in new browser window/tab but this cannot be recommended unless you tell the users somehow (e.g. with an icon) which links will open new windows/tabs. Expert web users know how to open every link in new tab when they want so opening new tabs without telling them will only irritate them, while novice users can get completely confused where they are and try to use the back button in browser to return to page they were while they are in new window, which of course doesn't work.