Custom groups are perfect for when you want to build a group of references that are not easily found by index term or other common text. You can browse through your reference list and drag individual references to a custom group.
Create group sets in order to organize your custom groups and smart groups. See Group Sets.
Custom groups and smart groups are listed alphabetically within each group set. Click the My Library header at the top of the Groups panel to toggle between ascending and descending order.
To get started with custom groups, see: