Fever, a self-hosted feed reading alternative to Google Reader, lets you add feeds to multiple groups. This is handy if you want to make sure you don’t miss a site’s articles or if a site writes about more than one topic you care about.

If you’re adding one or more of a site’s feeds via the Feedlet bookmarklet (found in your Fever settings), click the Options button next to each feed, hold the Command key (Control on Windows) while selecting more than one group for that feed, then save your work.

For feeds already in your Fever, hit the Gear menu and enable “Show Feeds.” Then, mouseover a feed, click its RSS icon, choose “Edit Feed,” hold Command to select multiple feeds, and save your work.