It would be cool to have several options (if users wish to use it this way) - and I get this may be a total pain from an IT perspective to actually set up. 1. Creator of notebook can grant tagging privileges to users in shared notebooks. This is separated privilege from editing/deleting. 2. To limit clutter in the creator's other notebooks from members, have Tags for shared notebooks limited to that notebook (i.e concept of shared tags). 3. Add a search check box for global searches to "exclude shared notebooks" (Default to be to include them) when searching via tags. 4. Creator can delete / edit shared tags. Members can add tags, but not edit or delete them (mainly so someone can maintain a sense of order). 5. Creator can delegate one additional member with full admin privileges who can delete / edit shared notebook tags. Does that rambling make any sense?