I've been trying to tie some views together, and keep running into this property on the toolbar Tasks. It confuses me because I don't seem to be able to add my own Tasks to the toolbar (e.g. "Print" item) to make use of it.
Could you give a simple example as it applies to a core Joomla component (e.g. Categories or Articles) showing how it would be used? The popup help says "Reuse the ID value of the item in another request var. ex: filter_category=[ID]", but I don't understand why someone would use it on one of the pre-defined tasks on the toolbar (why would I "edit" anything other than the selected item, so what does "filter_category" accomplish by adding it to the task property?)