It’s Facebook Friday — each week we’ll offer one tip for leveraging Facebook to increase customer awareness of and engagement with your brand or business.

Facebook’s policy for Cover Photos is simple, but it’s pretty well buried in Facebook’s general guidelines, and to make matters difficult, it recently changed. To help you make sure you make a good impression on customers and stay on your digital host’s good side, we’ve got the details of what you can and can’t do — and specifics on what’s changed.

Let’s start with the guidelines that were already around before Facebook’s big addition in January. First, Cover Photos are required by Facebook to be at least 399 pixels wide, but if you care about quality, you’ll amp it up to the actual size of the space: 851 pixels wide by 315 tall. If you don’t go all the way, your image will be grainy and make a poor impression. The 399 number is just the one that Facebook specifies as the bare minimum in its terms.

Additionally, the classic guidelines say that your Cover Photo can’t contain any of the below items. (We’re drawing the wording straight from Facebook’s Pages guide book to avoid any mix-ups.)

• Price or purchase information, such as “40% off” or “Download it at our website”
• Contact information, such as web address, email, mailing address or other information intended for your Page’s About section
• References to user interface elements, such as Like or Share, or any other Facebook site features
• Calls to action, such as “Get it now” or “Tell your friends”

The addition, which was announced in December and put into effect on January 15, is that text may not occupy more than 20% of your cover photo’s area. Facebook has promised to release a tool that will scan your image to help you determine if it’s in violation, but without it you’ll just have to count pixels. Using the full dimensions? Don’t use more than 170 x 63 pixels of that image to house text.

If you want an example of a Facebook Cover Photo that keeps well within the limit while still getting its message across, take a look at Spotify’s Page. Good design sense can help you overpower restrictions.