When creating a photo book in Lightroom, if you’ve positioned a text caption some­where on your page and you want to make sure it doesn’t get moved accidentally (when you’re swapping out images or moving cells), just click on the square with a small black square inside that ap­pears on the edge of the caption field. It will fill with yellow, showing that its position is now locked. To unlock it, click on that same little square again.

Excerpted from The Adobe Photoshop Lightroom CC Book for Digital Photographers by Scott Kelby.