A system for providing collaborative tag sets to assist in the navigation and use of a folksonomy. The collaborative tag sets are social in nature. As more users group two tags together into tag sets, the disclosed system causes the association between those two tags to grow stronger, as exposed in the bookmark system user interface when alternative tags are suggested for browsing the bookmarks in a folksonomy. Tags that are grouped together by a user into a tag set have the strongest possible weight for that user, and accordingly the disclosed system automatically applies all tags in a set when that user is retrieving bookmarks if the user selects at least one of tags in the set. Tags not in the user's tag sets, but included in the public tag set(s) of another user(s) are displayed in the user interface as tag suggestions.