This TIP proposed to allow users to save and reuse the set of list filters for a template::list list.
This would allow a user to build a "view" of a list that includes the ordering, grouping, and other filters to be reused. Used on a dynamic list that allows showing and hiding columns this can be very powerful.
See: http://solutiongrove.info/zen/planets for a working example of this. Note the user interface is not part of this proposal. It is just an example of one way to design an interface to save and resuse filters.
Functionally there are a couple of tcl procedures added that will save the filters into a generic CR content item that is keyed to the url, list name, and the filter properties. From this a user interface to load a previously saved set of filters can be created.