There are a lot of terrific new features in OS X El Capitan. But given how much time I spend reading in Safari, my current favorite is tab pinning. If you are an old hand at this, move along, nothing to see here.

New to El Capitan? Give this a try:

• Open up a new window
• Open up your favorite web site
• Click the site’s tab (the area under the title bar, to the left of the +) and drag it to the left until it turns into a mini tab, then release it. You’ll need to be within about half an inch of the left edge of the window for the pin mechanism to kick in.

The tab will be marked with the site’s mini icon, typically in the form of a single letter (the Loop is an L, Daring Fireball a D, the New York Times a fancy T).

• Open a few more sites, drag them to the left, until you’ve got 3 or 4 tabs pinned on the left.

To revisit one of the pinned sites, click on its tab. To expand a tab, drag it back to the right. Easy peasy.

But the real value of tabs doesn’t emerge until you do this:

• With a few tabs pinned to the left, open a new Safari window.

Your pinned tabs will be pinned in the new window, too.

I find this incredibly useful when I am making my way through my morning site visits. As I find stories I want to read in depth and, perhaps, comment on in The Loop, I accumulate those tabs, pinning them as I go. A pinned tab takes up very little tab bar real estate and let’s me keep a few unpinned tabs to work with as I work on a specific story.