String variables may require value labels as well. For example, your data may use single letters, M or F, to identify the sex of the subject. Value labels can be used to specify that M stands for Male and F stands for Female.

Click the Variable View tab at the bottom of the Data Editor window.

Select the Values cell in the sex row and click the button to display the Value Labels dialog box.

Type F for the Value and Female for the Value Label.

Click Add to have this label added to your data file.

Repeat the process, but this time type M for the Value and Male for the Value Label.

Click OK to implement your changes and return to the Variable View.

Because string values are case sensitive, you should make sure you are consistent with your cases. A lower case m is not the same as a capital M.