With Safari in OS X El Capitan there’s a Pin Tab entry on the Window menu but no keyboard shortcut. To create a pinned tab you’re forced to use the mouse to drag an existing tab to the left of the Safari window, or right-click the tab and select the option.
However, this lack of keyboard shortcut is easily fixed using OS X’s built-in tools, as follows.
- Open System Preferences and click the Keyboard icon.
- Click the Shortcuts tab, and in the list at the left at the left click the App Shortcuts entry.
- Click the Plus button, located in the middle bottom of the window.
- In the dialog box that slides into view, select Safari from the Application dropdown list.
- In the Menu Title field below, type Pin Tab.
- Click in the Keyboard Shortcut field beneath this, and press whatever shortcut you want. Ctrl+Cmd+P is a good choice, but beware that Cmd+P is usually assigned to File > Print.
- Click Add, then close System Preferences.