YaST/Style Guide/Dialogs/Suggested Values

From openSUSE

Suggested Values

Use editable combo boxes when you want to give the user the possibility to select preselected option or to set his own option.
The most commonly used values can be provided as suggested values within a combo box.
Please keep in mind not to overfill a combo box with possibilities. Try not use more than five items in a combo box.

Example

This combo box of the Sudo module in YaST can be either edited.

...or the user can select some suggested values.