Value lists are a way for project managers to define a list of values from which field values can be chosen . The ability to pick from a predefined list of values is important, particularly when the field will be used for filtering, sorting, or grouping a view. When the field used for such purposes has all hand-entered values, misspellings can possibly invalidate the sort or grouping. This can leave tasks or resources out of the filter. Selecting from a predefined list ensures that there are no misspellings or typographical errors to cause filter errors.
Creating a Value List
Click Tools, Customize, Fields from the menu bar.
Select the field for which you want to define a list.
Click the Value List button.
Enter the values into the grid.
Use the Up and Down buttons to move values into the desired position in the list.
Setting a Default Value
Click Tools, Customize, Fields from the menu bar.
Select the field for which you want to define a list and click the Value List button.
Select the Use a Value From The List As The Default Entry for the Field option.
Select the entry that should be the default value.
Click the Set Default button.
The default list item will be shown in red. This value will appear by default for all new tasks.
For Your Information
Losing Field Values
After you create a value list for a field and close the Customize Fields dialog, any previous values stored in the field will be lost. Project will warn you of this, but you should be aware of it before you start building the list.
Click Tools, Customize, Fields from the menu bar. 
Select the field for which you want to define a list. 
Click the Value List button. 
Enter the values into the grid. 
Use the Up and Down buttons to move values into the desired position in the list. 
The default list item will be shown in red. This value will appear by default for all new tasks. 
