The Caps Lock key on Mac keyboards often feels a little unnecessary, since it’s easy enough to hold the Shift key while typing multiple capital letters for acronyms like HIPPA or when you want to shout GET OFF MY LAWN! But if you need to do that on an iPhone or iPad, it can be annoying to keep tapping the Shift key to switch to the uppercase keyboard for each letter. Luckily, Apple has baked a time-saving trick into its onscreen keyboard to help you out. Tap the Shift key twice in a row to lock it on, type the letters you need, and tap it again to unlock it. Notice that when Shift is locked on, a small horizontal line appears beneath the arrow on the Shift key.