When you type in characters after a slash or question mark, make sure you enter them in the correct case. For example, ask vi to search for IN, and type the word in uppercase. You will see that vi prints the message Pattern not found . As it turns out, this file does not contain the word IN in uppercase, although it has the word several times in lowercase.

Notice that the message used the word Pattern. In a vi command, anything after a slash or question mark is called a pattern.