The underscore mark on your keyboard is something you may have rarely used. It is often used as a substitute for a space when a space is not permitted. For example, when defining variables in the database programming language MYSQL, the underscore is often used to define variables. Another use for the underscore is to separate words in a user name. Many user names, for example e-mail user names, don't allow for spaces. Therefore, the underscore is a good way to separate words in an e-mail user name.
Type a letter or word that must be separated by an underscore.
Locate the "Hyphen" key on your keyboard. This is directly to the right of the "0" key.
Press the "Shift" button on your keyboard. This is found in the lower left corner of your keyboard.
Press the "Hyphen" key while still holding the "Shift" key. This creates the underscore on your computer screen.