Sometimes it is useful to look up a topic in the same way you would look it up in a paper Encyclopedia - manually. Perhaps you are unsure of the precise spelling, or maybe you are interested in a word root which has many applications, such as "self-". Wikipedia has an index of all of its articles, with a few ways available for accessing it. The first is the Wikipedia:Quick index, also presented as "A-Z index" on the Main Page. The next is the All pages item in the Special pages menu accessible from the left sidebar in the toolbox menu. The last method of accessing Wikipedia's index is the with this link: Special:Prefixindex, which you can place on your user page or a talk page for convenient access. Type the beginning of the article's name into the Display pages with prefix box and press Go. You will now see a list of all pages which begin with what you typed. You can reduce the number of articles displayed in this list by typing more of the name and pressing Go again. You can also find Wikipedia users in a similar way by changing the entry in the drop-down box labelled Namespace, from Main to User.
Read more: Wikipedia: Special pages