[edit] What is wrong with bare URLs?

Bare URLs are subject to link rot. The following Bare URLs are all links that can rot:

• http://support.nikontech.com/app/answers/detail/a_id/14083
• [1]
• Nikon D2X Firmware update 2.0.0 for Windows

Each of these URLs is depending on the target WWW site retaining its chosen site structure, which it is under no obligation to do.

Similarly, all of these bare URL citations of the International Herald Tribune have rotted, since the New York Times restructured the IHT's WWW site:

• [2]
• [3]
• [4]

A proper citation, in contrast, gives the author, title, publisher, publication, and date of the work. Even if the link rots, the new location of the thing being cited can be found from the full information given. Moreover, the thing being cited can, with the full information present, be found in other ways, such as in printed form, microfiche archives, article/paper collections published as books, and the like.

This is what a full citation for the Nikon article might look like, using the {{cite web}} template:

• "Answer ID 14083: D2X Firmware update 2.0.0 — Windows". Find Answers. Nikon USA Inc.. 2008. http://support.nikontech.com/app/answers/detail/a_id/14083. Retrieved 2009-05-09. 

This is a full citation of the first International Herald Tribune article, using the {{cite news}} template:

• David Colman (2007-02-01). "Hans Wegner, 92, broke ground with Danish Modern chair designs". International Herald Tribune. http://www.iht.com/articles/ap/2007/02/01/europe/EU-GEN-Denmark-Obit-Wegner.php. 

Notice that with the full information, it is still possible to retrieve the IHT article, via services such as LexisNexis, Highbeam Research, and others, even though the IHT's own WWW page was taken down.

Secondary problems with bare URLs are that they are ugly, and can affect the display of a page. For example, this bare URL causes page widening:

• http://support.nikontech.com/cgi-bin/nikonusa.cfg/php/enduser/std_adp.php?p_faqid=14083&p_created=1159553141&p_sid=PMjnxbji&p_accessibility=0&p_lva=&p_sp=cF9zcmNoPSZwX3NvcnRfYnk9JnBfZ3JpZHNvcnQ9JnBfcm93X2NudD03JnBfcHJvZHM9MTksMTQ3JnBfY2F0cz0xODYmcF9wdj0yLjE0NyZwX2N2PTEuMTg2JnBfc2VhcmNoX3R5cGU9YW5zd2Vycy5zZWFyY2hfbmwmcF9wYWdlPTE*&p_li=&p_topview=1