Some web designers think that people don't understand their browser and start to clutter pages with what I call browser functionality. Quite often this is used when all window chrome has been removed. Note that some browsers are able to prevent the removal of window chrome. Some examples are described below.
Not really browser functionality but most visitors already have a clock on their computer. And one is enough, really
Before scripting languages in some bad designs a "back" link or button (also known as "previous") was added to each page. This was a link to the page the designer considered the previous page. However with hyper linking there is no such thing as a fixed previous page.
With use of a scripting language like JavaScript it is possible to mimic the behavior of the back button of the browser. But why should this functionality be added to the page? It only takes valuable space. I recommend against using a back or previous button especially when they lead to a page which from the visitor's point of view isn't the previous one.
Even worse: some sites use javascript: in the value of the href
attribute of the a element, making a link that doesn't work when JavaScript is
off. Also, such links can't be opened in a new tab with Firefox.
Adding a page to favorites or bookmarks is already supported by the browser. So no need to add this to your page. Visitors not able to add a page as a bookmark by themselves are most likely not able to use bookmarks at all.
Once again this is also quite clearly supported by the browser. On the other hand, sites use a print button or link to open a page that is optimised for printing purposes. Especially when frames are used this can be a very good option to display a version without the menu and such, which I recommend.
Modern browsers support the option to open a new window when the user requires this. So leave this up to your visitor, also because it breaks the functionality of the back button on most browsers since the history is not copied to the new window.
Most people are aware how to close a window so no need for a "close this window" link. The one exception is when window chrome has been removed and there is no other obvious way to close the window.