Show above is the first use case diagram for etags which shows that a visitor needs to be able to View, Add, and Remove tags, and also view images of a visitor, while a site owner needs to be able to remove any tag and configure the software.
It also shows that all functionality communicates with the eTag database (which will store tags, etc.) and also that when adding a tag it communicates with facebook to make a post on the user’s wall “You have been tagged….”
I will post more UML diagrams soon. Stay tuned….