Tagging in the Slate is a fairly straight-forward extension of the way that tags are implemented on the Tk canvas. Any item can be tagged. For example, given some item citem, we can write
$slate addtag "fred" withtag $citem
Some time later, we could write
$slate move "fred" -10 0which would move citem, including all of its components, ten pixels to the left. (Any other item tagged with ``fred'' will also be moved.) Any node in the hierarchy can be tagged in this way, and performing an operation on the tag will operate on the corresponding subtree of the hierarchy.