This could be a 5 star extension, it is the best available for what it does. I do however wish I could manipulate more than 1 variable for the regex captures, for example to combine part of the :pagetitle: and part of the :pageurl: into a single filename. Currently it only works with one or the other, unless you don't customize the variable and take the whole mess to create one giant filename. Alternatively a regex replace option could offer the cleanup needed prior to saving. Also, if this extension could be triggered via javascript or an extension that would be amazing, would love to be able to use hotkeys to pass a resource url to Save-In... for acquisition.