An innovative powerful feature: It allows a group manager to pre-define a set of groups tags as "recommended group tags" to improve group tagging consistency, or as a form of scaffolding to provide models of tags. These "recommended group tags" will automatically show up each time this group is selected in the bookmarking window:

Many possible use scenarios. For example, perfect for teachers to guide students for a more structured group bookmarking activities. Note: special credit to Steve Hargadon of Classroom2.0 for making this feature request!