Remove canvas shapes by tag?

Hello all, new to the list (hopefully this has not been asked) I've created a global canvas called *main-canvas* and have attached a few shapes to it. (create-line* *main-canvas* `(,x ,y ,x2 ,y2) :tags "line") Am I specifying the tag correctly for the new line instance or does it need to be in a list? Also, how would I tell a canvas to remove all and only items with the "line" tag attached? Sincerely, Ryan