Add/Remove Lists
Add/remove lists are lists where the user can add or remove rows. The following sets out a series of design patterns that can be used for this type of list. It is an elaboration and extension of the existing design guidance that can be found in the HIG.
Add/remove lists are appropriate when content items are only presented for addition, removal and editing. This is distinct from cases when rows represent items to be navigated or viewed (selection mode is an alternative design pattern to consider in these situations). A bookmark editing dialog is a good example of appropriate add/remove list usage.
Tentative Design
https://raw.githubusercontent.com/gnome-design-team/gnome-mockups/master/theming/widgets/add-remove-lists/add-remove-lists.png